What ways are there to disrupt spellcasting in 5e?

[Myth27]

So preparing an action to attack when the enemy cast doesn’t work anymore. Are there feats or abilities that let you do it? (Other than counterspell)

Edit: I would also be interested to know about any monsters/npc that can disrupt casting if you can think of any

[Unoriginal]

So preparing an action to attack when the enemy cast doesn’t work anymore. Are there feats or abilities that let you do it? (Other than counterspell)

If you mean "disrupt a spell that is currently being cast", then nope, there's none by RAW.

There is plenty of ways to make a spellcaster not able to cast, though. Like blocking their line of sight, blocking their hands, stopping them from talking, etc.

[Talionis]

Darkness can block line of sight. Silence stops spells with a verbal component. Anti Magic Field is a high level spell but does exactly what you want.

Mage Slayer feat is also useful. Also remember that at least half of all spells require concentration which can be broken with damage against a concentration check.

Interestingly a Shadow Monk has access to these spells and is Martial focused.

[Waazraath]

So preparing an action to attack when the enemy cast doesn’t work anymore. Are there feats or abilities that let you do it? (Other than counterspell)

Edit: I would also be interested to know about any monsters/npc that can disrupt casting if you can think of any

Grapple to prevent somatic / material components, maybe even verbal depending on DM?

As for monsters: the beholder's anti magic cone, of course, and afb, but I think it was the demi lich that has a legendary action (or lair action) that works as an antimagic field that targets 1 person.

[Dungeon-noob]

Hit them really, really hard. High damage means difficult concentration check. Giving them disadvantage on those first also really helps.

[Captain Bob]

If you're targeting a non-arcane caster that won't have the shield spell, magic missile is a good choice - three concentration checks for an auto-hit first level spell

ALSO - higher level arcane tricksters and monster hunter rangers have a few neat reactions that sort of do this

[Aquillion]

If you mean "disrupt a spell that is currently being cast", then nope, there's none by RAW.

There is plenty of ways to make a spellcaster not able to cast, though. Like blocking their line of sight, blocking their hands, stopping them from talking, etc.I believe you can ready an action to take when someone starts casting a spell (possibly even a specific spell, if you can make the Arcana check to identify it.)

In that case you can use any of those methods to stop them, although it would normally require magic yourself. For example, you could ready an action to cast Silence when the enemy starts to cast a spell. When they do so, you could roll Arcana to determine the spell, then decide if you want to silence it or not. The poor-man's counterspell, essentially - doesn't require a roll for high-level spells, but requires you ready your action in advance and only works on spells with verbal components.

[Naanomi]

A monk’s stun is a pretty efficient disruption to spell casting

[Throne12]

Grapple to prevent somatic / material components, maybe even verbal depending on DM?

As for monsters: the beholder's anti magic cone, of course, and afb, but I think it was the demi lich that has a legendary action (or lair action) that works as an antimagic field that targets 1 person.

Grapple doesn't effect anything but movement.

[JoeJ]

I believe you can ready an action to take when someone starts casting a spell (possibly even a specific spell, if you can make the Arcana check to identify it.)

In that case you can use any of those methods to stop them, although it would normally require magic yourself. For example, you could ready an action to cast Silence when the enemy starts to cast a spell. When they do so, you could roll Arcana to determine the spell, then decide if you want to silence it or not. The poor-man's counterspell, essentially - doesn't require a roll for high-level spells, but requires you ready your action in advance and only works on spells with verbal components.

A readied action goes after the trigger, so it can't stop the spell from being cast. And you can't use Arcana to identify a spell and then take a readied action because you only have one reaction per round.

[Aquillion]

A readied action goes after the trigger, so it can't stop the spell from being cast. And you can't use Arcana to identify a spell and then take a readied action because you only have one reaction per round.That's why you ready the action to go when they start casting the spell, rather than when they've cast it. Casting a spell takes time. (Note that the way readied spells work is that you cast it in advance, so you can easily outspeed their action with your reaction and unleash it in the sliver of time specified.)

You can absolutely interrupt other people's actions with your readied action like that as long as you specified what you were waiting for properly - otherwise the basic examples of eg. interrupting someone's movement wouldn't make sense ("yes, you readied an action to pull the lever when the cultist steps on the trapdoor, but it only goes off after their action, so they've already moved past it by the time you can react.")

And where does it say that using Arcana to identify a spell is a reaction? That would make it almost useless, since you wouldn't actually be able to do anything with the information you got (in particular, Arcana check + counterspell is pretty essential - without that, every single counterspell would have to be utterly blind.)

[Coffee_Dragon]

If you're targeting a non-arcane caster that won't have the shield spell, magic missile is a good choice - three concentration checks for an auto-hit first level spell

Has this been confirmed? The concentration rules specifically say you roll separate checks for damage from multiple sources, but a Magic Missile spell is a single source.

[Captain Bob]

https://twitter.com/jeremyecrawford/status/716012166101401600?lang=en

Probably as definitive as it's going to get - each missile is considered a 'source of damage'. This would apply with scorching ray, or ice-knife etc. as well.

[JoeJ]

That's why you ready the action to go when they start casting the spell, rather than when they've cast it. Casting a spell takes time. (Note that the way readied spells work is that you cast it in advance, so you can easily outspeed their action with your reaction and unleash it in the sliver of time specified.)

I don't expect that a lot of DMs would allow that interpretation. Of course, the only DM who matters is the one at your table, so you should check with them.


And where does it say that using Arcana to identify a spell is a reaction? That would make it almost useless, since you wouldn't actually be able to do anything with the information you got (in particular, Arcana check + counterspell is pretty essential - without that, every single counterspell would have to be utterly blind.)

It's in XGtE, p. 85. You can use your reaction to identify a spell as it's being cast, or an action to identify one afterward. And yes, Counterspell is always cast blind unless the enemy spellcaster stupidly announces in advance spell what they're casting. (And even if they did that, could you trust them?)

[Tanarii]

And yes, Counterspell is always cast blind unless the enemy spellcaster stupidly announces in advance spell what they're casting. (And even if they did that, could you trust them?)
Consider the idea of a (probably BBEG's minion) caster yelling Fireball when it's casting a Fire Bolt stolen. :smallamused:

[JoeJ]

Consider the idea of a (probably BBEG's minion) caster yelling Fireball when it's casting a Fire Bolt stolen. :smallamused:

You really shouldn't announce your attacks in advance (https://www.youtube.com/watch?v=3Nb3Z5te48M).

[Kane0]

Consider the idea of a (probably BBEG's minion) caster yelling Fireball when it's casting a Fire Bolt stolen. :smallamused:

Or just ‘BURN!’ Could be firebolt, burning hands, scorcher, scorching rays, flaming sphere, fireball, wall of fire...

[Unoriginal]

That's why you ready the action to go when they start casting the spell, rather than when they've cast it. Casting a spell takes time. (Note that the way readied spells work is that you cast it in advance, so you can easily outspeed their action with your reaction and unleash it in the sliver of time specified.)

You can absolutely interrupt other people's actions with your readied action like that as long as you specified what you were waiting for properly - otherwise the basic examples of eg. interrupting someone's movement wouldn't make sense ("yes, you readied an action to pull the lever when the cultist steps on the trapdoor, but it only goes off after their action, so they've already moved past it by the time you can react.")

And where does it say that using Arcana to identify a spell is a reaction? That would make it almost useless, since you wouldn't actually be able to do anything with the information you got (in particular, Arcana check + counterspell is pretty essential - without that, every single counterspell would have to be utterly blind.)

Trying to abuse semantics is not going to work. You can't Ready an action to interrupt a spell anymore that you can Ready an action to interrupt a sword attack.

The trigger is the Action in-game, not a part of the action.

As for the identification taking a Reaction, the rules are in the Xanathar's. You're supposed to Counterspell blind.

[Kane0]

Trying to abuse semantics is not going to work. You can't Ready an action to interrupt a spell anymore that you can Ready an action to interrupt a sword attack.

The trigger is the Action in-game, not a part of the action.



Citation needed

[Aquillion]

Trying to abuse semantics is not going to work. You can't Ready an action to interrupt a spell anymore that you can Ready an action to interrupt a sword attack.Of course you can use a Ready action to interrupt a sword attack; I'm honestly shocked that anyone would suggest otherwise.

"I ready an action to do X moves to attack me" is, to me, one of the most basic usages of the Ready action. (Not capital-M moves, obviously.)

Again, one of the examples given in the book is "pull a lever while someone walks over a trapdoor." If you can't interrupt actions, that wouldn't make any sense (because you'd have to wait for them to finish their move, rendering the whole point of using a ready action for that moot.)


The trigger is the Action in-game, not a part of the action.So if I said "I ready an action to pull this lever if someone walks over that trapdoor", you would say "fine, but it only works if they end their move on it, otherwise you can't interrupt them?"

The game isn't a computer program; words mean what they mean in plain English. Nothing in the Ready Action rules implies that you have to key it to a capital-A action. All it cares about is a "perceivable circumstance". And the example it gives specifically has you cutting into an enemy's movement. Here's what it says:


Sometimes you want to get the jump on a foe or wait for a particular circumstance before you act. To do so, you can take the Ready action on your turn, which lets you act using your reaction before the start of your next turn.

First, you decide what perceivable circumstance will trigger your reaction. Then, you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it. Examples include "If the cultist steps on the trapdoor, I'll pull the lever that opens it," and "If the goblin steps next to me, I move away."

When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger. Remember that you can take only one reaction per round.

No limits like what you're saying on the "perceivable circumstance." DMs might reasonably object if you try to slice time too thinly to allow yourself time to react, but that isn't a problem with the examples given.

The whole point of the Ready Action (as it says) is to get the jump on your foe. Of course you can ready an action to respond to someone who's about to attack you.


I don't expect that a lot of DMs would allow that interpretation.If they want to nerf the ready action, that's their call, but by my reading, "I ready an action to do [X] if someone begins to [Y]" (or halfway through Y or whatever) is the main purpose of the ready action - it allows you to cut in at key moments in ways that wouldn't otherwise be possible, at the cost of delaying your action, making it contingent on what happens, and possibly wasting it. The "you go after the trigger" wording just establishes that you need to have some sort of percievable trigger to react to and can't psychically act before you had any reason to think you should (ie. you can pull the lever as soon as you see someone, but you can't use that to pull the lever before someone steps into view.)

I think the vast majority of DMs would allow, it, though? It's clearly both RAW and RAI, and it isn't exactly powerful enough to require some sort of "you can only react to discrete capital-A Actions" ruling. Especially given that, again, your interpretation would make it mostly impossible to do the Ready Action laid out as an example.

Like, I'll be honest, most of the objections you and Unoriginal are raising seem baffling to me - I can neither understand how you could possibly interpret the Ready Action rules that way, nor why you would want to. The whole point of a Ready Action is to let you act just in time - if you had to specify an entire capital-A action as a trigger (and, therefore, go after that action was totally complete), you wouldn't be able to do much with it at all and would lose out on most of the creativity or reward for anticipating your enemies' actions that it offers.

Breaking out of the limits of the Action system to try and pull something (that you hope is) clever is the entire point.

[Rukelnikov]

Of course you can use a Ready action to interrupt a sword attack; I'm honestly shocked that anyone would suggest otherwise.

"I ready an action to do X moves to attack me" is, to me, one of the most basic usages of the Ready action. (Not capital-M moves, obviously.)

Of course, so much so, that the game already has such reactions :S Like Light Cleric's Warding Flare, a GOOLock's Entropic Ward, or the Protection Style.

[ProsecutorGodot]

Of course you can use a Ready action to interrupt a sword attack; I'm honestly shocked that anyone would suggest otherwise.

The issue with this logic is that both the examples given are related to using an enemies movement as the trigger. Movement is incremental and triggering a lever after they've stepped onto a trapdoor follows all rules for Ready Action.

If your trigger is an attack or spellcast being made though, these involve a defined process where "after the trigger" is only met once the attack is fully resolved or the spell has been cast (unless the spell has a casting time longer than 1 action, but that's not relevant here).

It's not possible to interrupt an action, you can only respond to it.

[JoeJ]

If they want to nerf the ready action, that's their call,

It's not a house rule, it's a ruling. If your DM rules otherwise, then that's how it will work at that table.


Like, I'll be honest, most of the objections you and Unoriginal are raising seem baffling to me - I can neither understand how you could possibly interpret the Ready Action rules that way, nor why you would want to. The whole point of a Ready Action is to let you act just in time - if you had to specify an entire capital-A action as a trigger (and, therefore, go after that action was totally complete), you wouldn't be able to do much with it at all and would lose out on most of the creativity or reward for anticipating your enemies' actions that it offers.

The rule is that you take your readied action right after the trigger finishes, not right after it starts. That's the RAW.

[Waazraath]

Grapple doesn't effect anything but movement.

Yeah, I know, but it is also an opposed athletics check, and skill rules are described in a notoriously limited way. What you can do exactly is up to the table conventions and DM, and I can imagine quite some would allow an opposed athletics when grappling to restrain a targets arms and / or prevent speaking.

[Rukelnikov]

The issue with this logic is that both the examples given are related to using an enemies movement as the trigger. Movement is incremental and triggering a lever after they've stepped onto a trapdoor follows all rules for Ready Action.

If your trigger is an attack or spellcast being made though, these involve a defined process where "after the trigger" is only met once the attack is fully resolved or the spell has been cast (unless the spell has a casting time longer than 1 action, but that's not relevant here).

It's not possible to interrupt an action, you can only respond to it.

There are examples of it happening in the PHB already (Light Cleric's Warding Flare, a GOOLock's Entropic Ward, or the Protection Style). Such a reaction goes after the attack has started and before it is resolved.


The rule is that you take your readied action right after the trigger finishes, not right after it starts. That's the RAW.

Exactly, if the trigger is "when he steps on the plate", once he sets foot on it the trigger has been completed.

Similarly, if the triggers is "when he starts casting", the trigger is fulfilled when he started it.

It would be different if the trigger was "when the cleric casts bless I shoot", in that case the trigger would not be completed until the spell has finished being cast successfully.

[Unoriginal]

Please, could you tell us when the "X foe starts casting a spell" trigger finishes?

[ProsecutorGodot]

There are examples of it happening in the PHB already (Light Cleric's Warding Flare, a GOOLock's Entropic Ward, or the Protection Style). Such a reaction goes after the attack has started and before it is resolved.

Those are exceptions, and they don't interrupt the trigger (in the sense of preventing it from happening) they change the outcome.


Please, could you tell us when the "X foe starts casting a spell" trigger finishes?

This is reminding me of when Crawford said "There is no taking the attack action, the attack just happens"

Seems relevant in the sense that there isn't an intent for such a trigger to exist.

[JoeJ]

Similarly, if the triggers is "when he starts casting", the trigger is fulfilled when he started it.

The trigger has to finish, not just start.

[TheUser]

So preparing an action to attack when the enemy cast doesn’t work anymore. Are there feats or abilities that let you do it? (Other than counterspell)


Gonna need a citation of some kind here.

The fantasy trope of a caster having a crossbow bolt plunge into his neck/hand/chest as he begins casting a spell only to be stifled by the trauma or have their intricate verbal/somatic components disrupted adequately is pretty common in medieval fantasy.

Even the idea of a guy stuffing his hand into the face of a mage before he finished casting a spell has been used. It's definitely a trope in these types of stories to say the least.

Even in older editions this has been a widely used mechanic so I need some definitive RAW support or at the very least some Sage Advice(*shudder*).

Oh and just to quash any doubts about this ridiculous notion that a caster gets to finish casting before you can interrupt with a readied action. If the trigger is "they start casting a spell" once they have started the trigger is resolved and your action goes off. They need not finish casting. There is loads of reactions that already function off of interrupting an action before it completes (counterspell being the most appropriate example; which literally describes using a reaction to interrupt a spell).


3rd-level abjuration

Casting Time: 1 reaction, which you take when you see a creature within 60 feet of you casting a spell.

Range: 60 feet

Components: S

Duration: Instantaneous

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell’s level. On a success, the creature’s spell fails and has no effect.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used.

[ProsecutorGodot]

Gonna need a citation of some kind here.

The fantasy trope of a caster having a crossbow bolt plunge into his neck/hand/chest as he begins casting a spell only to be stifled by the trauma or have their intricate verbal/somatic components disrupted adequately is pretty common in medieval fantasy.

Even the idea of a guy stuffing his hand into the face of a mage before he finished casting a spell has been used. It's definitely a trope in these types of stories to say the least.

Even in older editions this has been a widely used mechanic so I need some definitive RAW support or at the very least some Sage Advice(*shudder*).

Oh and just to quash any doubts about this ridiculous notion that a caster gets to finish casting before you can interrupt with a readied action. If the trigger is "they start casting a spell" once they have started the trigger is resolved and your action goes off. They need not finish casting. There is loads of reactions that already function off of interrupting an action before it completes (counterspell being the most appropriate example; which literally describes using a reaction to interrupt a spell).


3rd-level abjuration

Casting Time: 1 reaction, which you take when you see a creature within 60 feet of you casting a spell.

Range: 60 feet

Components: S

Duration: Instantaneous

You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell’s level. On a success, the creature’s spell fails and has no effect.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used.

I'm not sure that citing the only reaction that explicitly allows you to interrupt a spell being cast opens the door to an arrow serving the same function.

It's an exception, a very very specific one at that.

[Unoriginal]

I find it funny that some people argue that it's totally possible to disrupt a spell when "it starts being cast" with an attack by using Counterspell as a precedent, because if it was possible it would make Counterspell worthless for its level.

From level 1 onward, any character can Ready an action to attack, at melee or at range. A ranged Rogue in particular would be in a golden position to shut down any caster that shows up, given using a Reaction for it doesn't diminish their number of attacks per turn most of the time, especially given they can still do things with their bonus action. Even a caster can Ready Firebolt or Create Bonfire or Vicious Mockery or the like to cast "when the enemy starts the spell", and so (according to the people who argue for it) can disrupt other casters at range.

Meanwhile Counterspell costs you one of your spell known, and a non-negligible spell slot. For something at best slightly more effective than a cantrip, because it doesn't use an Action to Ready and sometime auto-cancel the target.

If Fireball was only slightly better than Firebolt or Create Bonfire, then it'd be pretty worthless, too. But no one is arguing that it should be the case.


You can put your hand on the mouth of a caster to prevent then from casting. You can't throw a rock a caster mid-cast to shut them up. Unless you want to make Counterspell be worth as much as Greater Thrown Rock.

[Theodoric]

Wait, why would a simple damage spell like Firebolt completely interrupt spellcasting? It might damage the caster, but that's not a guarantee of disrupting a spell even if that spell requires concentration

[Unoriginal]

Wait, why would a simple damage spell like Firebolt completely interrupt spellcasting? It might damage the caster, but that's not a guarantee of disrupting a spell even if that spell requires concentration

If Firebolt can't (as the rules say) disrupt spellcasting, why would a sword or a arrow be able to?

As I said, Counterspell doesn't use an action, and sometime auto-cancel the spell. It's still not worth its spell level if the only differences are that a Readied Firebolt uses an action and requires a save from the hit caster.

[ProsecutorGodot]

Trying to abuse semantics is not going to work. You can't Ready an action to interrupt a spell anymore that you can Ready an action to interrupt a sword attack.

The trigger is the Action in-game, not a part of the action.

As for the identification taking a Reaction, the rules are in the Xanathar's. You're supposed to Counterspell blind.


Citation needed

Just to go back and touch on this chain, the reason you can't interrupt a sword attack (which is functionally the same reason you can't interrupt a spell cast) is because of the specified timing.

We know that a Readied Action happens after the chosen trigger. Let's work under the assumption that you have chosen "when they start to attack me" as a trigger.

We need to observe the rules for Making an Attack now, which go as follows in a 3 step process:
1 - Choose a target. They haven't begun to attack you.
2 - Determine modifiers. They still haven't begun to attack you.
3 - Resolve the Attack. They have finally rolled their d20 and are making an attack roll against you. As soon as this is finished you can attack them back with your readied action.

If there's ever any question whether something you're doing counts as an attack, the rule is simple: if you're making an attack roll, you're making an attack.

The steps to casting a spell are even simpler, it just happens.

There isn't a point where they are considered to "start attacking" that can end without the attack resolving. It's the same with spells, there isn't a point in casting a spell that you can interrupt it (except when you are specifically allowed, in the case of Counterspell and spells with a casting time longer than one action) where they "start casting" without it resolving in the same step.

[TheUser]

I find it funny that some people argue that it's totally possible to disrupt a spell when "it starts being cast" with an attack by using Counterspell as a precedent, because if it was possible it would make Counterspell worthless for its level.

From level 1 onward, any character can Ready an action to attack, at melee or at range. A ranged Rogue in particular would be in a golden position to shut down any caster that shows up, given using a Reaction for it doesn't diminish their number of attacks per turn most of the time, especially given they can still do things with their bonus action. Even a caster can Ready Firebolt or Create Bonfire or Vicious Mockery or the like to cast "when the enemy starts the spell", and so (according to the people who argue for it) can disrupt other casters at range.

Meanwhile Counterspell costs you one of your spell known, and a non-negligible spell slot. For something at best slightly more effective than a cantrip, because it doesn't use an Action to Ready and sometime auto-cancel the target.

If Fireball was only slightly better than Firebolt or Create Bonfire, then it'd be pretty worthless, too. But no one is arguing that it should be the case.


You can put your hand on the mouth of a caster to prevent then from casting. You can't throw a rock a caster mid-cast to shut them up. Unless you want to make Counterspell be worth as much as Greater Thrown Rock.

Oof, not a fair comparison at all

A readied attack is one attack (as opposed to 2-3 on a person's turn) and carries the risk of the player readying the attack to not have the trigger happen and their turn essentially wasted.

Counterspell has none of these pitfalls. But let's really get into the details shall we?

Counterspell vs a readied attack

Counterspell: Guaranteed if the spell slot used is of equal level to spell cast, costs one reaction, the spell caster being countered still expends a spell slot.

Readied attack: not guaranteed since it requires a successful attack roll and possibly a failed concentration check (DM dependant), it also requires both an action and a reaction on a pre-determined gamble; if the readied circumstance doesn't happen then the player has wasted their turn, and most importantly, since the requirements of the spell are not met when the target is interrupted by an attack (you've disrupted one of the spell's components, be it verbal, somatic or material) it doesn't technically get cast and no spell slot is consumed.

While the ability to compare the two with regards to reaction mechanics exists, the buck stops there I'm afraid.

[Unoriginal]

So you think that those advantages are worth the spell being as high level as Fireball?

[ProsecutorGodot]

Oof, not a fair comparison at all

A readied attack is one attack (as opposed to 2-3 on a person's turn) and carries the risk of the player readying the attack to not have the trigger happen and their turn essentially wasted.

Counterspell has none of these pitfalls. But let's really get into the details shall we?

Counterspell vs a readied attack

Counterspell: Guaranteed if the spell slot used is of equal level to spell cast, costs one reaction, the spell caster being countered still expends a spell slot.

Readied attack: not guaranteed since it requires a successful attack roll and possibly a failed concentration check (DM dependant), it also requires both an action and a reaction on a pre-determined gamble; if the readied circumstance doesn't happen then the player has wasted their turn, and most importantly, since the requirements of the spell are not met when the target is interrupted by an attack (you've disrupted one of the spell's components, be it verbal, somatic or material) it doesn't technically get cast and no spell slot is consumed.

While the ability to compare the two with regards to reaction mechanics exists, the buck stops there I'm afraid.

Then how is it a fair comparison to use Counterspells ability to interrupt spells as a confirmation that a readied attack can do the same thing? Counterspell has specific wording to allow it to function in such a way, I don't see any such wording under "Longsword" or "Arrow" in the equipment section, or under the Readied Action section for that matter.

[TheUser]

Just to go back and touch on this chain, the reason you can't interrupt a sword attack (which is functionally the same reason you can't interrupt a spell cast) is because of the specified timing.

We know that a Readied Action happens after the chosen trigger. Let's work under the assumption that you have chosen "when they start to attack me" as a trigger.

We need to observe the rules for Making an Attack now, which go as follows in a 3 step process:
1 - Choose a target. They haven't begun to attack you.
2 - Determine modifiers. They still haven't begun to attack you.
3 - Resolve the Attack. They have finally rolled their d20 and are making an attack roll against you. As soon as this is finished you can attack them back with your readied action.


The steps to casting a spell are even simpler, it just happens.

There isn't a point where they are considered to "start attacking" that can end without the attack resolving. It's the same with spells, there isn't a point in casting a spell that you can interrupt it (except when you are specifically allowed, in the case of Counterspell and spells with a casting time longer than one action) where they "start casting" without it resolving in the same step.

Except that you can interrupt a sword attack with a reaction already...several actually.

Bend Luck, Cutting Words...the shield spell.

And all of them happen after the roll.

Don't try and say a reaction can't interrupt a sword swing when there are several examples of known features that do exactly that. It's not some niche either, several reaction based features across feats, spells and class abilities all exist to literally expend a reaction to stop a sword mid swing.

[TheUser]

Then how is it a fair comparison to use Counterspells ability to interrupt spells as a confirmation that a readied attack can do the same thing? Counterspell has specific wording to allow it to function in such a way, I don't see any such wording under "Longsword" or "Arrow" in the equipment section, or under the Readied Action section for that matter.


Versimillitude.

I'd say it's at the heart of D&D's appeal.

[Unoriginal]

Except that you can interrupt a sword attack with a reaction already...several actually.

Bend Luck, Cutting Words...the shield spell.

And all of them happen after the roll.

Don't try and say a reaction can't interrupt a sword swing when there are several examples of known features that do exactly that. It's not some niche either, several reaction based features across feats, spells and class abilities all exist to literally expend a reaction to stop a sword mid swing.

None of those abilities interrupt the sword attack. They can turn a hit into a miss, but they can't prevent the attack from happening.

You can't Ready an Hold Person spell a footsoldier mid-strike, either.

[ProsecutorGodot]

Except that you can interrupt a sword attack with a reaction already...several actually.

Bend Luck, Cutting Words...the shield spell.

And all of them happen after the roll.

Don't try and say a reaction can't interrupt a sword swing when there are several examples of known features that do exactly that. It's not some niche either, several reaction based features across feats, spells and class abilities all exist to literally expend a reaction to stop a sword mid swing.

Again, you didn't interrupt the attack. It still happened, you just changed the resolution with a feature that is specifically allowed to do so. Those features explicitly list that they can be used in such a way. Specifics trump general, those are all specifics.

Your attack action, with an arrow or sword, does not have such wording attached. There is no specific or general reason that it would be allowed to interrupt a spell or melee strike.


Versimillitude.

I'd say it's at the heart of D&D's appeal.
And if you're going to run it that way at your table, that's your right and I encourage that. Don't proclaim that it's the way it must be run because there's plenty of evidence against it.

OP wanted a RAW way to interrupt spellcasting other than counterspell, unfortunately, no such method exists. That doesn't mean you can't make one.

Citing Verisimilitude as a reason for it being a fair comparison is also ridiculous, by the way. Your proposal that a mundane arrow can completely debilitate a spellcaster who just the last turn maintained his concentration through the raging torrent of electricity released from the maw of a thousand-year-old behemoth of a dragon because the kobold waited for his hands to move in a particular way is absolutely absurd to me.

Or maybe I just don't want my players to think a Shortbow is a suitable replacement for Counterspell.

[Contrast]

So generally reactions occur after the trigger unless specified. Whether a DM will let your trigger include that specification is up to them.

I would say that if they had intended for this to be how ready actions work I would expect that to be how Mage Slayer works whereas it isn't.

I would highlight that only spells with a casting time of longer than 1 action require concentration (obviously otherwise casting any spell would break concentration) and if you're attacking before they've finished casting even a concentration spell wouldn't have its concentration up. So RAW as far as I can see attacking someone in the middle of casting a spell does nothing and in many cases would actually be worse than attacking them after they cast as you wouldn't be able to mess with concentration.

So you need a DM to rule that casting all spells requires concentration in addition to ruling that when the ready action specifies 'after the trigger finishes' it means 'after the trigger finished unless otherwise specified' to make this work. The first ruling is actually more important than the second as its a major nerf to generally casting spells while maintaining concentration without even considering someone trying to use ready actions.

[ThePolarBear]

The trigger is the Action in-game, not a part of the action.

Not really. The trigger has to be a "perceivable occurrence". The ones doing the perceiving are the characters, so it has to be "something that happens in fiction". That's also why you can't ready when a particular roll is made.

It is totally fine and required for the trigger to be something that ends up being part of an action, such as "unsheating" or "weaving the staff around".

However:


Of course you can use a Ready action to interrupt a sword attack; I'm honestly shocked that anyone would suggest otherwise.

You can never ready to "interrupt" something. You ready to react to something after that something happens, because you have to perceive it happening for the trigger to be triggered.

What the trigger is is the important part.

For spellcasting, however, there would be a need to know if it is possible to identify casting and how to do so, and even if there's the possibility to do so, the trigger would need to be something that is always part of that process.

And even once you actually "interrupt" the casting, nothing would really happen: all one action spells do not require concentration to cast (so you aren't really disrupting anything) and spells that require concentration to maintain do not require concentration until they are cast (and if you are interrupting the process of casting, the spell still hasn't been cast).
Longer casting time spells would require concentration saves regardless of when you strike.

Result: you are better off, most of the time, just attacking during your turn. And, if you are in a standoff, there are better triggers to set.

Furthermore, i'm still of the opinion that you can't never really perceive something "starting". At most, you can perceive that something "has started": it requires at least a modicum of observation to really understand when the "something" you are looking at actually comes into fruition:

Is a person that looks at you menacingly, with a big sword, that's swinging towards you ACTUALLY making an attack? What if they stop just shy of hitting you?

[TheUser]

You can't Ready an Hold Person spell a footsoldier mid-strike, either.

Why not?
You really need to back up these claims you espouse as true.

Also you are right, they turn hits into misses. My bad. I forgot that this debate is about interrupting spells and not interrupting attacks.

Regardless, Sentinel will suffice.
Sage Advice tells us that sentinel triggers before the attack resolves, ergo the damage sentinel can do has the potential to kill a creature before they complete their attack. Boom attack interupted.

[ProsecutorGodot]

Why not?
You really need to back up these claims you espouse as true.

Also you are right, they turn hits into misses. My bad. I forgot that this debate is about interrupting spells and not interrupting attacks.

Regardless, Sentinel will suffice.
Sage Advice tells us that sentinel triggers before the attack resolves, ergo the damage sentinel can do has the potential to kill a creature before they complete their attack. Boom attack interupted.

No, it says no such thing.


Sentinel
Does the attack granted by the third benefit of the Sentinel feat take place before or after the triggering attack?
The bonus attack takes place after the triggering attack.Here’s why: the feat doesn’t specify the bonus attack’s timing, and when a reaction has no timing specified, the reaction occurs after its trigger finishes (DMG, 252). In contrast, an opportunity attack specifically takes place before its trigger finishes—that is, right before the target creature leaves your reach (PH, 195).

You really need to back up these claims you espouse as true.

[TheUser]

No, it says no such thing.



You really need to back up these claims you espouse as true.

My bad, I knew I read it on twitter somewhere. Guess it's not Sage Advice. Still, a lead game designer :P

https://twitter.com/mikemearls/status/518783306033553410

[ProsecutorGodot]

My bad, I knew I read it on twitter somewhere. Guess it's not Sage Advice. Still, a lead game designer :P

https://twitter.com/mikemearls/status/518783306033553410

If you read literally two tweets down (https://twitter.com/mikemearls/status/518792711869325312) on that chain he also says that Readied Actions occur after the trigger.

Mike Mearls is a great creative mind (in my opinion) but he's not a terrific source for rules or their intentions (also my opinion).

[Solusek]

Why not?


Ready actions happen after the event that triggers them. If you ready to cast hold person when the soldier attacks, FIRST THE SOLDIER ATTACKS (attack roll, damage, everything). Then your hold person spell goes off.

[Unoriginal]

he's not a terrific source for rules or their intentions (also my opinion).

It's also his own opinion, if it matters.


Ready actions happen after the event that triggers them. If you ready to cast hold person when the soldier attacks, FIRST THE SOLDIER ATTACKS (attack roll, damage, everything). Then your hold person spell goes off.

Thank you.

[ProsecutorGodot]

It's also his own opinion, if it matters.

I hope I didn't come across in a way that implied someone isn't entitled to their own opinion, I just don't think citing Mike Mearls opinion suddenly makes the RAW change.

Just to clear the air a bit, my whole opinion on this is:
RAW - There is no way to "interrupt" a spell cast or attack other than counterspell or other such features that explicitly allow you to do so.
RAI - Seems to match RAW in most cases. The sample size is a bit small though.
RAF - You do you fam. If it makes sense at the time for it to happen, go for it.

[Unoriginal]

I hope I didn't come across in a way that implied someone isn't entitled to their own opinion, I just don't think citing Mike Mearls opinion suddenly makes the RAW change.

I meant that it's his own opinion he isn't a terrific source of rules.

[Naanomi]

None of those abilities interrupt the sword attack. They can turn a hit into a miss, but they can't prevent the attack from happening.

You can't Ready an Hold Person spell a footsoldier mid-strike, either.
I guess the question may be... can the ‘trigger’ be something other than an action or movement? I know a common trigger for readied actions at the tables I’ve been in is ‘whenever they are within range of...’ or ‘as soon as I can see...’ which generally happen because of movement, but not always. Or, a recent example, a PC was acting as a guard to a thief who had slipped their bonds before... can they ready an action for when they start struggling, or do they politely wait until they’ve escaped the ropes before beginning to grapple?

Can I ready until they lose concentration on a spell (assuming that the spell is a perceivable effect)? Can I ready until the start of their turn? If I ready ‘when they come into range’ in a way that is between their movement and a potential action they wanted to do at that range?

Also, for examples of Reactions that seem to pre-empt the event that triggered them: Magic-User’s Nemesis

[ProsecutorGodot]

I guess the question may be... can the ‘trigger’ be something other than an action or movement? I know a common trigger for readied actions at the tables I’ve been in is ‘whenever they are within range of...’ or ‘as soon as I can see...’ which generally happen because of movement, but not always.

Can I ready until they lose concentration on a spell (assuming that the spell is a perceivable effect)? Can I ready until the start of their turn? If I ready ‘when they come into range’ in a way that is between their movement and a potential action they wanted to do at that range?

Also, for examples of Reactions that seem to pre-empt the event that triggered them: Magic-User’s Nemesis

Just in case there are people (like me) who completely forgot about this ability, it's a Monster Slayer Ranger ability.

At 11th level, you gain the ability to thwart someone else’s magic. When you see a creature casting a spell or teleporting within 60 feet of you, you can use your reaction to try to magically foil it. The creature must succeed on a Wisdom saving throw against your spell save DC, or its spell or teleport fails and is wasted.

Once you use this feature, you can’t use it again until you finish a short or long rest.
Which functions similarly to Counterspell, even sharing much of the same wording.

Counterspell
You attempt to interrupt a creature in the process of casting a spell. If the creature is casting a spell of 3rd level or lower, its spell fails and has no effect. If it is casting a spell of 4th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell fails and has no effect.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the interrupted spell has no effect if its level is less than or equal to the level of the spell slot you used.
So it would also be able to interrupt a spell being cast. The Monster Hunter Ranger actually seems to have a few effects that specifically let you pre-empt the trigger of your reaction, as the 15th level Slayer's Counter also happens before it's trigger.

At 15th level, you gain the ability to counterattack when your prey tries to sabotage you. If the target of your Slayer’s Prey forces you to make a saving throw, you can use your reaction to make one weapon attack against the quarry. You make this attack immediately before making the saving throw. If your attack hits, your save automatically succeeds, in addition to the attack’s normal effects.

That's the issue though, is that these features specify timing whereas Readied Actions always happen after their trigger, regardless of what the trigger is or what you readied as an action.

[ThePolarBear]

I guess the question may be... can the ‘trigger’ be something other than an action or movement?

Any perceivable occurrence can be a trigger for the Ready Action.
It's a misconception that it has to be an "action" or movement at all. It can even be something that is completely unrelated to the target, like a leaf falling.

[JackPhoenix]

My bad, I knew I read it on twitter somewhere. Guess it's not Sage Advice. Still, a lead game designer :P

https://twitter.com/mikemearls/status/518783306033553410

Even back when tweets were still acceptable as rules answers, Mearls' tweets weren't. Only Crawford's tweets carried any weight, and that changed earlier this year. Now only SA compendium matters.

[tieren]

I don't think I would allow "when target starts to cast a spell" as a trigger at my table. Personally I think it is too vague to say its a perceivable event. Is it when the wizard opens his mouth? waves his hands? When his focus starts to glow? What if they have subtle spell?

I do think I would allow any of those specific triggers (i.e. when the wizard opens his mouth, or moves his hands, etc...).

I would allow the readied attack/spell to take place right at one of those triggers, and if it hit and killed the caster, whatever he was starting to do wouldn't complete (whether it was casting a spell or opening his mouth to say "I surrender"). If it didn't kill him I would then have the caster complete the spell (assuming the readied action didn't impose some effect to prevent that [blind, silence, etc...]). Caster can of course use his reaction to counterspell any readied spell.

I don't think mechanically its that different than just using the attack action the turn before. At my table you can't ready an action outside of initiative, that is actually what initiative is for.

[stoutstien]

So ways to disrupt spellcasters
Steal or destroy spell focus. Order domain channel + shatter is a good one.
Toss a blanket or bedroll over the caster
Pocket sand
Alchemist fire, hunting trap, or any other form of continual damage that takes an action to stop.

[TheUser]

I don't think I would allow "when target starts to cast a spell" as a trigger at my table. Personally I think it is too vague to say its a perceivable event. Is it when the wizard opens his mouth? waves his hands? When his focus starts to glow? What if they have subtle spell?

I do think I would allow any of those specific triggers (i.e. when the wizard opens his mouth, or moves his hands, etc...).

I would allow the readied attack/spell to take place right at one of those triggers, and if it hit and killed the caster, whatever he was starting to do wouldn't complete (whether it was casting a spell or opening his mouth to say "I surrender"). If it didn't kill him I would then have the caster complete the spell (assuming the readied action didn't impose some effect to prevent that [blind, silence, etc...]). Caster can of course use his reaction to counterspell any readied spell.

I don't think mechanically its that different than just using the attack action the turn before. At my table you can't ready an action outside of initiative, that is actually what initiative is for.

Clearly this wouldn't work with Subtle spell (since the spell is no longer observable) but to somehow assume that regular speech and invoked spells are similar infers that regular talking and "chanting mystic words" (PHB 203 for Vocal Component) are somehow interchangeable comes off as....disingenuous. People don't accidentally talk themselves in to casting spells do they? (For the love of Bahamut can we all agree that "chanting mystic words" sounds different than spoken language?)

However, one could surmise that because counter spell exists the ability to perceive when a caster has begun to cast a spell and the ability to interrupt it with a reaction before it finishes is entirely within the scope of rules-worthy situations, by simply exchanging a counter spell with a readied attack the interactions within the scope of the action economy and the ability to emulate this with other interactions now exists.

If you have your sights trained on a wizard, with crossbow loaded and already aimed, you have a few seconds to fire off your shot before the spell completes right? (otherwise why does the spell have a casting time as opposed to just an action cost?) The ability to discern regular speech vs invoked spells has already been covered implicitly by the rules of counter spell, which is to say, even in a heated battle, if a person within 60ft of you invokes a verbal, material or somatic component to a spell, it is so obvious that you as a player know it's happening (the potential for a deception check to imitate a spell by the target also exists....which would still probably end up using the deceiver's action....a niche but possible scenario).

The point being made is that to say "you can use your reaction to counter a spell with the wave of your hand (counterspell has only a somatic component) but not the pulling of a crossbow trigger or the release of a readied bow attack" reeks of double standard.

Both embody reactions. Why can only one interrupt the spell but the other one can't?

[ProsecutorGodot]

The point being made is that to say "you can use your reaction to counter a spell with the wave of your hand (counterspell has only a somatic component) but not the pulling of a crossbow trigger or the release of a readied bow attack" reeks of double standard.

Both embody reactions. Why can only one interrupt the spell but the other one can't?
Magic. Literally Magic.

You're not just waving your hand at them, you're using a precisely applied bit of magic to interrupt them. An arrow does not have the same effect.

[TheUser]

Magic. Literally Magic.

You're not just waving your hand at them, you're using a precisely applied bit of magic to interrupt them. An arrow does not have the same effect.

Perhaps we view magic as a very different thing.

I view casting a spell as a highly calibrated action that involves delicate precision in both voice and hand movements as well as a mental focus and clarity (hence why people dedicate their lives to mastering even menial levels of magic)

To infringe on any of those elements can upend one's ability to invoke magic and bend the weave.

If your precisely tuned hand motions for a somatic component or masterfully performed and precise vocal component is interrupted with a crossbow bolt/arrow to the hand or a brief stifling of voice as you wince from pain and gasp for air as you take a crossbow bolt to the chest can interrupt that carefully orchestrated performance.

Saying "because magic" seems lazy.

Counterspell, whilst magic, still operates on the action economy, and thus far, I've demonstrated that the way it interacts with the action economy allows for reactions to be used to interrupt spells.

[KorvinStarmast]

Grapple to prevent somatic / material components, maybe even verbal depending on DM?
Nothing in grapple restricts spell casting. If using the grappler feat and applying the restrained condition, there still isn't a constraint on spell casting, unless one attempts to do that and the DM applies a DC to that effort. (Some kind of opposed check, I imagine)

[TheUser]

I don't mean to spam the thread but I've also found something that might be useful to the debate:

https://www.sageadvice.eu/2015/12/11/can-silence-interrupt-a-spell-caster/

Using a readied spell to interrupt a spell seems completely within the allowances of the lead game designer as DM.

[KorvinStarmast]

I don't mean to spam the thread but I've also found something that might be useful to the debate:

https://www.sageadvice.eu/2015/12/11/can-silence-interrupt-a-spell-caster/

Using a readied spell to interrupt a spell seems completely within the allowances of the lead game designer as DM. If I may follow up on the interrupt/block/nullify a sword attack: unless you are a gladiator NPC with the NPC parry feature, a feature that "interrupts" an attack isn't generally available for free. (This feature is kinda like the shield spell)
Reactions
Parry: The gladiator adds 3 to its AC against one melee Attack that would hit it. To do so, the gladiator must see the attacker and be wielding a melee weapon. Even the battlemaster's parry doesn't completely nullify the attack

Parry. When another creature damages you with a melee Attack, you can use your Reaction and expend one superiority die to reduce the damage by the number you roll on your superiority die + your Dexterity modifier. Unless your roll and mod are equal to or greater than the damage of the attack.

[Waazraath]

Nothing in grapple restricts spell casting. If using the grappler feat and applying the restrained condition, there still isn't a constraint on spell casting, unless one attempts to do that and the DM applies a DC to that effort. (Some kind of opposed check, I imagine)

Yes, exactly. (see also my post #24)

[stoutstien]

Nothing in grapple restricts spell casting. If using the grappler feat and applying the restrained condition, there still isn't a constraint on spell casting, unless one attempts to do that and the DM applies a DC to that effort. (Some kind of opposed check, I imagine)
Problem now is a break in game logic.
A DM can call for a concentration check if they are on a rocking boat(example given in PHB) but not if a 300 Kg barbarian tackles them.
Gagged isn't a condition so guess that's out also

[KorvinStarmast]

Problem now is a break in game logic.
A DM can call for a concentration check if they are on a rocking boat(example given in PHB) but not if a 300 Kg barbarian tackles them.
Gagged isn't a condition so guess that's out also I don't know if that's a break in game logic, since "gagged" can be ruled as effective without being a condition. (Call it a gross version of the silence spell ...) and the DM can call for that con check, but is not required to.
Welcome to 5e, rulings over rules. That's a feature, not a bug.

Yes, exactly. (see also my post #24) Hmm, not sure how I missed that, I tossed that post in, and maybe I was speed reading page 1. We are in violent agreement, it seems. :smallsmile:

[Rukelnikov]

There's nothing in the rules that says taking damage during casting disrupts the spell being casted, that is a classic trope of DnD (and maybe medieval fantasy in general), but currently that would land squarely in homerules, not even rulings.

However, the ready action in the PHB says: "First, you decide what perceivable circumstance will trigger your reaction. Then, you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it. Examples include "lf lhe cultist steps on the trapdoor, I'll pull the lever that opens it," and "If the goblin steps next to me, I move away."

We have precedent as to what can be perceived and what cannot. Beginning to cast a spell can clearly be perceived since Counterspell says "You attempt to interrupt a creature in the process of casting a spell", which means, after someone started casting a spell, and before it has finished casting it. Dealing damage in this situation wouldn't stop the spell from being cast (unless it downs the caster), but applying some conditions would, incapacitated for example.

Regarding interrupting an attack, the swing of the sword is a "perceivable circumstance", and there are many in game features that key off of an attack being made and take effect before the dice are rolled (as has been shown in this thread multiple times already). In the same vein as with the spell being cast, damaging an attacker wouldn't prevent the attack from being resolved, however applying certain conditions would.

And finally, about the "after the trigger" (which wouldn be a problem for any of the above examples sin the trigger had already happened in both of them), that's not even always the case, AoO are trigger of an enemy leaving your reach, but you can attack them anyway, and with Sentinel for example, they didn't even move. It is the attempt to leave reach that triggers AoO.

[ProsecutorGodot]

Counterspell, whilst magic, still operates on the action economy, and thus far, I've demonstrated that the way it interacts with the action economy allows for reactions to be used to interrupt spells.
No, you've demonstrated that Counterspell (and Magic-Users Nemesis) is able to be used to interrupt spells. Just because Counterspell has wording in it that allows it to interrupt a spell being cast and cause it to fail does not mean that any reaction can do the same. Not every action is the same, not every bonus action is the same and not every reaction is the same.

I don't mean to spam the thread but I've also found something that might be useful to the debate:

https://www.sageadvice.eu/2015/12/11/can-silence-interrupt-a-spell-caster/

Using a readied spell to interrupt a spell seems completely within the allowances of the lead game designer as DM.

And this is a fine enough ruling, it makes enough sense. This doesn't set a universal precedent.

And finally, about the "after the trigger" (which wouldn be a problem for any of the above examples sin the trigger had already happened in both of them), that's not even always the case, AoO are trigger of an enemy leaving your reach, but you can attack them anyway, and with Sentinel for example, they didn't even move. It is the attempt to leave reach that triggers AoO.
Just because AoO is a reaction doesn't mean it follows the same rules as Ready Action. Ready Action has its own rules, AoO has its own rules, spells cast as a reaction have their own rules (counterspell requires a spell to be cast, feather fall requires a creature within sight to fall)

Comparing them is apples to oranges, they're entirely separate things.

[Naanomi]

Magic. Literally Magic.

You're not just waving your hand at them, you're using a precisely applied bit of magic to interrupt them. An arrow does not have the same effect.
Unless that arrow came from a Monster Hunter Ranger, then it maybe does

[Rukelnikov]

No, you've demonstrated that Counterspell (and Magic-Users Nemesis) is able to be used to interrupt spells. Just because Counterspell has wording in it that allows it to interrupt a spell being cast and cause it to fail does not mean that any reaction can do the same. Not every action is the same, not every bonus action is the same and not every reaction is the same.

It doesn't need to be the same, either you can identify a spell being cast, or you don't. If you can it is a perceivable circumstance, and thus a valid trigger for Ready action.

[Coffee_Dragon]

We have precedent as to what can be perceived and what cannot. Beginning to cast a spell can clearly be perceived since Counterspell says "You attempt to interrupt a creature in the process of casting a spell", which means, after someone started casting a spell, and before it has finished casting it.

What you're doing here is zig-zagging between game and non-game logic:

There are two types of reactions, those that explicitly interrupt and those that don't.

Those that do interrupt must rely on being able to notice something about to happen.

But those who don't interrupt also involve noticeable things.

Therefore, they should also be able to interrupt.

Therefore, there aren't two types of reactions.

[ProsecutorGodot]

Unless that arrow came from a Monster Hunter Ranger, then it maybe does

Well it does say that you're magically foiling them, so it's still magic :thog:


It doesn't need to be the same, either you can identify a spell being cast, or you don't. If you can it is a perceivable circumstance, and thus a valid trigger for Ready action.
There isn't a "casting" process for single action spells. The spell takes effect, triggers your readied action.

In the context of Counterspell, the spell fails because of the magical influence, not necessarily because you interrupted any of the spells components. I'd even go so far as to wager that the way counterspell is intended (this is my opinion) to work is that they finish all the component parts of casting the spell and at the very moment that the magic would normally happen is your window to counter.

[Rukelnikov]

There isn't a "casting" process for single action spells. The spell takes effect, triggers your readied action.

But there clearly is, the trigger for counterspell is "which you take when you see a creature within 60 feet of you casting a spell". By all accounts it is a perceivable circumstance.


In the context of Counterspell, the spell fails because of the magical influence, not necessarily because you interrupted any of the spells components. I'd even go so far as to wager that the way counterspell is intended (this is my opinion) to work is that they finish all the component parts of casting the spell and at the very moment that the magic would normally happen is your window to counter.

That is your interpretation, the trigger, and the text imply otherwise "You attempt to interrupt a creature in the process of casting a spell.".

[ProsecutorGodot]

But there clearly is, the trigger for counterspell is "which you take when you see a creature within 60 feet of you casting a spell". By all accounts it is a perceivable circumstance. That is your interpretation, the trigger, and the text imply otherwise "You attempt to interrupt a creature in the process of casting a spell.".
There's also the final line of Counterspell "On a success, the creature's spell fails and has no effect."

It doesn't say anything about preventing the spell from being cast. This leads me to believe that even if you allow a trigger of "when I see them casting a spell" your attack lacks a property to cause the spell to fail and have no effect.

[Rukelnikov]

There's also the final line of Counterspell "On a success, the creature's spell fails and has no effect."

It doesn't say anything about preventing the spell from being cast. This leads me to believe that even if you allow a trigger of "when I see them casting a spell" your attack lacks a property to cause the spell to fail and have no effect.

Sure, I've said before that attacks don't disrupt spellcasting in 5e. But casting Hold Person would.

[darkrose50]

So preparing an action to attack when the enemy cast doesn’t work anymore. Are there feats or abilities that let you do it? (Other than counterspell)

Edit: I would also be interested to know about any monsters/npc that can disrupt casting if you can think of any

Some sort of magical item or effect that takes magical energy and converts it to something else. Perhaps this magical item also takes things created by magic and turns them into magic to be converted into something else. You may not want to use a wand around this magical item or effect.

A good example would be a forge. All magic around the forge would be converted to heat. Conjure an anvil in orbit, drop it onto the furnace, and the anvil would be converted to heat. Contingencies could go beyond this level. Perhaps any magic that would interfere with the forge would be absorbed. Magically pushing an asteroid so that it would hit the forge would be stopped by the forge converting that magical power to fire and heat.

[ProsecutorGodot]

Sure, I've said before that attacks don't disrupt spellcasting in 5e. But casting Hold Person would.

I disagree, I think the spell would take effect and the Hold Person triggers afterward. This could work well against a concentration spell, but not an instantaneous one.

[Rukelnikov]

I disagree, I think the spell would take effect and the Hold Person triggers afterward. This could work well against a concentration spell, but not an instantaneous one.

But, whats your basis for the spell being cast if Hold Person went thru?

[ProsecutorGodot]

But, whats your basis for the spell being cast if Hold Person went thru?

It happens after because that's how Readied Actions work. They're not Counterspell.

[tieren]

However, one could surmise that because counter spell exists the ability to perceive when a caster has begun to cast a spell and the ability to interrupt it with a reaction before it finishes is entirely within the scope of rules-worthy situations, by simply exchanging a counter spell with a readied attack the interactions within the scope of the action economy and the ability to emulate this with other interactions now exists.



I do not accept the premise that because a fifth level wizard is able to tell when a spell is being cast within 60 feet of him that everyone else in the world now is also.

Or that there is inherently some incredible difference in how casting Suggestion sounds compared to just making a suggestion.

But even if you allow the trigger and there is an attack, without some specific rule for it to stop spellcasting that turn it would have no effect on the casting process, RAW.

If the process were so intricate and delicate would you be able to do it while moving 30 feet? What if there was an attack of opportunity during the movement?

The bigger issue here is the action economy the round before. The attack the round before would probably have been better than the reaction attack anyway, so if a PC wants to waste a round in combat readying to do a single weapon attack on the NPC turn, I don't see how it breaks anything (and is a specific strategy of a Hasted rogue). You can't ready an action before combat begins (or at least initiative) so it isn't a way to handle most social/stand off situations.

[Aquillion]

Problem now is a break in game logic.
A DM can call for a concentration check if they are on a rocking boat(example given in PHB) but not if a 300 Kg barbarian tackles them.
Gagged isn't a condition so guess that's out alsoSort of. The real issue here isn't what calls for a concentration check (that's up to the DM), but the fact that in 5e, spellcasting itself never requires a concentration check, only maintaining your concentration on a spell you've already cast. The rocking boat example, say, might be required to maintain your concentration on Bigby's Hand, but it wouldn't be required to cast Fireball.

I think it's reasonable for a grapple to require a concentration check for ongoing spells, just based on the examples given in the text; but requiring a concentration check to cast a spell at all in adverse circumstances would require a houserule (albeit a reasonable-seeming one.) Before making that houserule I would hesitate and consider why they removed that rule in the transition from 3e to 5e.


I do not accept the premise that because a fifth level wizard is able to tell when a spell is being cast within 60 feet of him that everyone else in the world now is also.
I think it's important to remember, again, that it's not a computer game - things actually happen in reality. When someone casts a spell, they go through a series of actions - they reach for their spell component pouch, they start moving their hands to make obviously-magical gestures, they begin chanting verbal components. All of those are obvious visual signifiers of "they are about to cast a spell" or "they have started casting a spell" (you could argue that a spell with no component has no such signifiers, though, and therefore doesn't trigger a readied action of this sort.)

Also, it's important to realize that when you ready an action to cast a spell, you cast the spell in advance, on your turn, then hold it (using concentration, so this benefit isn't free!) until you decide to release it. Outspeeding their casting by waiting for the moment they reach for their spell component pouch, begin making magic gestures, or start to chant is therefore entirely reasonable, since you've already completed all those steps for your spell and they haven't.

[ProsecutorGodot]

I think it's important to remember, again, that it's not a computer game - things actually happen in reality. When someone casts a spell, they go through a series of actions - they reach for their spell component pouch, they start moving their hands to make obviously-magical gestures, they begin chanting verbal components. All of those are obvious visual signifiers of "they are about to cast a spell" or "they have started casting a spell" (you could argue that a spell with no component has no such signifiers, though, and therefore doesn't trigger a readied action of this sort.)

Also, it's important to realize that when you ready an action to cast a spell, you cast the spell in advance, on your turn, then hold it (using concentration, so this benefit isn't free!) until you decide to release it. Outspeeding their casting by waiting for the moment they reach for their spell component pouch, begin making magic gestures, or start to chant is therefore entirely reasonable, since you've already completed all those steps for your spell and they haven't.
You've caught yourself under the same false premise.

Remember that the timescale of a round of combat is 6 seconds. Both of those spellcasters are preparing their spells in the same 6 seconds, we just have to "gameify" it for the purposes of... playing the game. The actions in a round don't necessarily happen sequentially like they would be structured in Initiative, Reactions especially.

The expectation that you would be able to successfully recognize a spell being cast and react to it with anything that isn't specially designed to cause it to fail (IE, Counterspell) isn't very likely. You have to treat it like a game to reach the conclusion that the enemy spellcaster just waited for you to finish preparing your spell before he tried to cast his own.

[tieren]

I think it's important to remember, again, that it's not a computer game - things actually happen in reality. When someone casts a spell, they go through a series of actions - they reach for their spell component pouch, they start moving their hands to make obviously-magical gestures, they begin chanting verbal components. All of those are obvious visual signifiers of "they are about to cast a spell" or "they have started casting a spell" (you could argue that a spell with no component has no such signifiers, though, and therefore doesn't trigger a readied action of this sort.)



In the earlier post I said I would allow the trigger of opening their mouth, moving their hands, etc...but I find "begin casting a spell" too vague.

Suppose you are engaged with a rogue charlatan, and to mock your wizard they start moving their hands in a similar fashion or chanting the same words. Would the trigger activate? He isn't "casting a spell" but every observable event is identical to as if he were.

And I still don't think there is an observable difference between a caster using the Command spell to tell you to flee and a terrified wizard yelling at you to flee. At least not one an 8 int barbarian would recognize.

[darkrose50]

This opinion is just how I would work things like this. Sometimes you should be able to react to the action beforehand, and other times you should be able to react to the action afterword. This bump should come from someplace. A feat, a class ability, some combination of ability scores or bonus to roll. It could be setting specific. Perhaps you can interrupt a wizard, but not a warlock. Perhaps there are two versions of magic missile, but the blue mage's guild knows the version that cannot be interrupted.

[1] <action> is declared . . . sometimes this can be the trigger
[2] <action is attempted> / dice are rolled . . . it seems like this is most often the trigger.
[3] Success or failure determined
[4] Degree of success or failure is determined / dice are rolled

Sometimes different things should trigger in different steps. Triggering after an action is declared would be more powerful then triggering after dice were rolled. Sometimes it would make sense (to me, or if designing an opponent) for a grandmaster swordsman to react to an attack before the roll. Now not every swordsman, those master swordsman may just have to wait and react after the dice roll is made. Perhaps if the grandmaster swordsman hits the opponent, then they do not get to roll their attack. All sorts of triggers can be used . . . hand them out to monsters and players.

I also would include magical gloves that grant a +2 STR (minimum 13), or the like. I would sometimes prefer a giving a bonus to the roll rather than the advantage rule. Someone rolling a number of dice equal to there STR bonus and keeping one sounds like a way to go to me.

[JoeJ]

If your precisely tuned hand motions for a somatic component or masterfully performed and precise vocal component is interrupted with a crossbow bolt/arrow to the hand or a brief stifling of voice as you wince from pain and gasp for air as you take a crossbow bolt to the chest can interrupt that carefully orchestrated performance.

Cool. So my kobolds can stop the PCs from ever casting a spell in combat at all. That will be awesome when they confront the dragon and its minions, and can't use spells. I can probably make the caster players wonder why they even bothered to show up for the game!

[Aquillion]

Cool. So my kobolds can stop the PCs from ever casting a spell in combat at all. That will be awesome when they confront the dragon and its minions, and can't use spells. I can probably make the caster players wonder why they even bothered to show up for the game!
Only if they fail their concentration checks! Also, the caster has to be hit and take damage, which is generally a Bad Thing that the players should be striving to avoid anyway.

But a more serious issue with this is that 5e doesn't actually have any rules requiring checks as you cast - readied actions have nothing to do with that. They could theoretically interrupt spells that require concentration as soon as they're cast, but trying to cancel a Fireball with a crossbow bolt would definitely require a houserule or an ad-hoc DM ruling or the like. As I said above, in 5e you don't have to make a concentration check to cast a fireball in a rolling ship in a storm at sea, at least not by default.

By default, concentration checks are just to maintain spells that specifically require concentration, and nothing else.

[Tanarii]

The problem us the Ready action was called ready action. It should have been called Delay action. It wasn't for historical reasons, but what a Ready action actually does in 5e is allow you to hold your action until after a specified event. Too many people incorrectly see it as holding your action to interrupt a specified event, sometimes attempting to justify thay view by pasing eventd. And the name of the action doesn't help.

The same mistaken view is typically the root cause of why some people think it makes perfect sense to Ready outside of combat. They've got the core purpose of the action wrong.

Specifically in reference to this thread, the core purpose of Ready isn't to interrupt spellcasting. It's to allow you to attack a spellcaster you couldn't attack on your turn because reasons, or because you otherwise want to attack after a spell has been cast.

[Aquillion]

The problem us the Ready action was called ready action. It should have been called Delay action. It wasnt for historical reasons, but what a Ready action actually does in 5e is allow you to hold you action until after a specified event. To many people see it as holding your action to interrupt a specified event. And the name of the action doesnt help.

The same mistaken view is the root cause of why some people think it makes perfect sense to Ready outside of combat. They've got the core purpose of the action wrong.

Specifically in reference to this thread, the core purpose of Ready isn't to interrupt spellcasting. It's to allow you to attack a spellcaster you couldnt attack on your turn because reasons, or because you otherwise want to attack after a spell has been cast.
What are you basing this on?

I absolutely think that a major purpose of the Ready action is to interrupt people, and if you want to convince me otherwise you're going to have to actually point to quotes from books, people who wrote them, etc. to illustrate otherwise, not just assert your beliefs and call everyone else "mistaken."

Because so far the only things I've seen in this thread that actually point to rules and intent rather than people's opinions were my quote of the Ready Action rules (which clearly allow wide latitude in terms of triggers) and a quote from a 5e developer explicitly stating they would allow Silence to interrupt casting.

Like I said, you can rule it however you want at your table, but I don't find your arguments convincing at all, and I don't think "the Ready action isn't meant to interrupt people" is a reasonable argument - at the very least, nobody has been able to turn up anything to support it in this thread outside of hand-wavy "who would allow this?" (The answer is me, as well as several other people who have posted here, because I believe it to be both RAW and RAI, as well as being the more logical outcome from an in-universe perspective and being more balanced in terms of what it allows people to do.)

[Coffee_Dragon]

I absolutely think that a major purpose of the Ready action is to interrupt people, and if you want to convince me otherwise you're going to have to actually point to quotes from books, people who wrote them, etc. to illustrate otherwise, not just assert your beliefs and call everyone else "mistaken."

Did people not yet point to PHB 193 and DMG 252? I think they may have.

[Rukelnikov]

The problem us the Ready action was called ready action. It should have been called Delay action. It wasn't for historical reasons, but what a Ready action actually does in 5e is allow you to hold your action until after a specified event. Too many people incorrectly see it as holding your action to interrupt a specified event, sometimes attempting to justify thay view by pasing eventd. And the name of the action doesn't help.

The same mistaken view is typically the root cause of why some people think it makes perfect sense to Ready outside of combat. They've got the core purpose of the action wrong.

Specifically in reference to this thread, the core purpose of Ready isn't to interrupt spellcasting. It's to allow you to attack a spellcaster you couldn't attack on your turn because reasons, or because you otherwise want to attack after a spell has been cast.

The ready action description gives us two examples of its use, one of them is literally interrupting another creatures movement:

"lf lhe cultist steps on the trapdoor, I'll pull the lever that opens it"

[Waazraath]

Hmm, not sure how I missed that, I tossed that post in, and maybe I was speed reading page 1. We are in violent agreement, it seems. :smallsmile:

Bloody right we are! How dare you! This calls for a duel!

[Aquillion]

Did people not yet point to PHB 193 and DMG 252? I think they may have.
I've cited PHB 193 repeatedly; it's one of the strongest pieces of support for my position. It clearly allows you to specify triggers with a huge amount of breadth, including eg. "when someone starts to do X...", provided that there's some reasonable sensory indicator that they're starting to do X. In that case, per DMG 252, your reaction has a clear timing and goes off after that indicator is met (ie. as they start casting their spell, not when they finish it.) The only restriction on your trigger is that you have to be able to perceive it; it's not limited to "a complete Action" the way people seem to have assumed above, and nothing in either part suggests that it is.

In light of that, the rules clearly do allow the sorts of reactions I'm describing, and were clearly intended to do so given that a developer has indicated he would allow them.

Obviously some people disagree with that interpretation, but they haven't really provided much support for that outside of "no, you're wrong"; in light of that, I find the strident way people are criticizing interrupting a spell with a reaction to be a bit startling given that forbidding it is, at best, a somewhat controversial DM call with no clear backing in the books.

It seems pretty clear to me that both the RAW and RAI are that you can specify a trigger of eg. "when someone starts to do X" or "when it's clear someone is about to do Y", and, provided you actually have a sensory indicator of that, you get to go after that indicator but before whatever you were concerned they might do. The only caveat is that you need to be able to reasonably determine (which is sometimes a DM call, but, again, we have one of the developers saying that "about to cast a spell" is a reasonable thing to perceive and therefore set a reaction for.)

[Coffee_Dragon]

The ready action description gives us two examples of its use, one of them is literally interrupting another creatures movement:

"lf lhe cultist steps on the trapdoor, I'll pull the lever that opens it"

This is not interruption, unless you mean that your action to open the trapdoor should trigger when the cultist is still on the adjacent tile.

[jh12]

In that case you can use any of those methods to stop them, although it would normally require magic yourself. For example, you could ready an action to cast Silence when the enemy starts to cast a spell. When they do so, you could roll Arcana to determine the spell, then decide if you want to silence it or not. The poor-man's counterspell, essentially - doesn't require a roll for high-level spells, but requires you ready your action in advance and only works on spells with verbal components.

If you have to wait until they start casting a spell, make an Arcana check to see if you can identify it, decide whether you want to cast your spell, then cast your spell, how is your spell going to be finish first so that it can prevent theirs? Surely just because you have an action readied doesn't mean it happens faster than it otherwise would have.

[Rukelnikov]

This is not interruption, unless you mean that your action to open the trapdoor should trigger when the cultist is still on the adjacent tile.

It interrupts the movement because if the cultist was charging at you, and you open the trap door under his feet, he never got to complete his movement to be adjacent to you.

[Rukelnikov]

If you have to wait until they start casting a spell, make an Arcana check to see if you can identify it, decide whether you want to cast your spell, then cast your spell, how is your spell going to be finish first so that it can prevent theirs? Surely just because you have an action readied doesn't mean it happens faster than it otherwise would have.

"When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs."

[jh12]

"When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs."

And that's why I don't like to post from memory.

[Max_Killjoy]

Ah, D&D, utterly exceedingly rules-forward and exacting even when it tries not to be.

[JoeJ]

I've cited PHB 193 repeatedly; it's one of the strongest pieces of support for my position. It clearly allows you to specify triggers with a huge amount of breadth, including eg. "when someone starts to do X...", provided that there's some reasonable sensory indicator that they're starting to do X. In that case, per DMG 252, your reaction has a clear timing and goes off after that indicator is met (ie. as they start casting their spell, not when they finish it.) The only restriction on your trigger is that you have to be able to perceive it; it's not limited to "a complete Action" the way people seem to have assumed above, and nothing in either part suggests that it is.

You seem to be reading rather selectively. The PHB text you're referring to reads, "When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger." The DMG text you refer to reads, "If a reaction has no timing specified, or the timing is unclear, the reaction occurs after its trigger finishes, as in the Ready action" (emphasis in both texts mine).

Contrast that with the description of opportunity attacks on p. 195 of the PHB: "The attack interrupts the provoking creature's movement, occurring right before the creature leaves your reach." The text explicitly says that an OA interrupts the movement that triggered it. The ready action has no such statement.

[Aquillion]

You seem to be reading rather selectively. The PHB text you're referring to reads, "When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger." The DMG text you refer to reads, "If a reaction has no timing specified, or the timing is unclear, the reaction occurs after its trigger finishes, as in the Ready action" (emphasis in both texts mine).

Contrast that with the description of opportunity attacks on p. 195 of the PHB: "The attack interrupts the provoking creature's movement, occurring right before the creature leaves your reach." The text explicitly says that an OA interrupts the movement that triggered it. The ready action has no such statement.Sure. But you can specify the trigger to be anything you can perceive, so "when someone starts to cast a spell" is clearly a valid trigger. And with that trigger, you get to cast your spell before theirs completes, interrupting it. That's straightforwardly how the RAW works - you go after your trigger, but you're not required to wait for the entire action of which your trigger was just one part.

The moment you start to reach for your spell component pouch, I get to cast my spell - I go after "JoeJ started to reach for his spell component pouch, indicating he was casting a spell", not after "JoeJ casts his spell", since my trigger was the former and not the latter. And that means that if I (eg.) cast Silence in your area, your spell fails because you can no longer complete its verbal components.

I think we're going in circles now? There's no way you fail to understand my position on that at this point.


Remember that the timescale of a round of combat is 6 seconds. Both of those spellcasters are preparing their spells in the same 6 seconds, we just have to "gameify" it for the purposes of... playing the game. The actions in a round don't necessarily happen sequentially like they would be structured in Initiative, Reactions especially.
Right , but... within those six seconds, I started casting my spell first (then delayed the final "release" until I saw you reaching for your spell component pouch.) That's the whole premise of initiative and readied actions - by beating your initiative and taking a readied action, I was able to get my spell off before yours.

They don't go off simultaneously; that would make a hash of the entire initiative and readied-action system. One of our spells goes off first (either the Silence or the one you were trying to cast.) And everything in the rules indicates that if I'm eg. waiting for you to reach for your spell component pouch before I cast, mine triggers first.

I mean... otherwise, by your "six seconds" argument, even if I cast Silence over you on my action, without a readied action, you could still say "alright, but this is all happening in six seconds, so before Aquillion's Silence takes effect I'm going to cast my spell." Obviously that's silly.

[JoeJ]

Sure. But you can specify the trigger to be anything you can perceive, so "when someone starts to cast a spell" is clearly a valid trigger. And with that trigger, you get to cast your spell before theirs completes, interrupting it.

I think we're going in circles now? There's no way you fail to understand my position on that at this point.

I understand that you think that there is some meaningful way to finish starting to cast a spell while you're still casting the spell. In the absence of any distinct phases of spell casting, I don't find that convincing.

[Coffee_Dragon]

It seems pretty clear to me that both the RAW and RAI are that you can specify a trigger of eg. "when someone starts to do X" or "when it's clear someone is about to do Y", and, provided you actually have a sensory indicator of that, you get to go after that indicator but before whatever you were concerned they might do.

And to me it seems absurd that they should put some kind of sub-game of clever wordings in the rule by implication. The intent is clear: there is a class of reactions which (by necessity or otherwise) interrupt other actions, and the default is non-interruption, Ready falling under this except as specially adjudicated by the DM (based on context, not wording subgame). It would make no sense to have an implied, "You can still have all your reactions interrupt as long as you remember to play the clever wording game, we're just leaving the nominal default in to punish the scrubs who forget or didn't yet realize that's what you're supposed to do." I don't credit the designers with being that bad at rules design and writing.

Given this view of the intent, I find no problem applying the rules as written. On someone else's turn, they choose an action and perform it. From the perspective of a Ready action, this is atomic. Once it resolves, there's a window where you can parse if the trigger occurred, at which point there isn't a meaningful distinction between "cast a spell" and "begins to cast a spell" - as it should be.

[JackPhoenix]

And I still don't think there is an observable difference between a caster using the Command spell to tell you to flee and a terrified wizard yelling at you to flee. At least not one an 8 int barbarian would recognize.

Well, there is. Command still has verbal component that's separate from the effect (the command itself). And it's not on wizard's list, so wizard can't cast it.

From SA compendium:

Is the sentence of suggestion in the suggestion spell the verbal component, or is the verbal component separate?
Verbal components are mystic words (PH, 203), not normal speech. The spell’s suggestion is an intelligible utterance that is separate from the verbal component. The command spell is the simplest example of this principle. The utterance of the verbal component is separate from, and precedes, any verbal utterance that would bring about the spell’s effect

[Kane0]

And to me it seems absurd that they should put some kind of sub-game of clever wordings in the rule by implication. The intent is clear: there is a class of reactions which (by necessity or otherwise) interrupt other actions, and the default is non-interruption
4e neatly handled this by splitting immediate actions into Reactions and Interrupts. Shame we didn't keep that.

For the record my table goes on Readied actions being able to interrupt, depending on the trigger of course.

[Rukelnikov]

I understand that you think that there is some meaningful way to finish starting to cast a spell while you're still casting the spell. In the absence of any distinct phases of spell casting, I don't find that convincing.

But there clearly is: "1 reaction, which you take when you see a creature within 60 feet of you casting a spell", "You attempt to interrupt a creature in the process of casting a spell"


And to me it seems absurd that they should put some kind of sub-game of clever wordings in the rule by implication. The intent is clear: there is a class of reactions which (by necessity or otherwise) interrupt other actions, and the default is non-interruption, Ready falling under this except as specially adjudicated by the DM (based on context, not wording subgame). It would make no sense to have an implied, "You can still have all your reactions interrupt as long as you remember to play the clever wording game, we're just leaving the nominal default in to punish the scrubs who forget or didn't yet realize that's what you're supposed to do." I don't credit the designers with being that bad at rules design and writing.

Given this view of the intent, I find no problem applying the rules as written. On someone else's turn, they choose an action and perform it. From the perspective of a Ready action, this is atomic. Once it resolves, there's a window where you can parse if the trigger occurred, at which point there isn't a meaningful distinction between "cast a spell" and "begins to cast a spell" - as it should be.

One of the two examples given for readying an action is "an interrupt", as you put it, how can you then say that the "deafult" is non-interruption?

[Aquillion]

And to me it seems absurd that they should put some kind of sub-game of clever wordings in the rule by implication. The intent is clear: there is a class of reactions which (by necessity or otherwise) interrupt other actions, and the default is non-interruption, Ready falling under this except as specially adjudicated by the DM (based on context, not wording subgame). It would make no sense to have an implied, "You can still have all your reactions interrupt as long as you remember to play the clever wording game, we're just leaving the nominal default in to punish the scrubs who forget or didn't yet realize that's what you're supposed to do." I don't credit the designers with being that bad at rules design and writing.From my perspective, the intent and rules as written are both clear and unequivocal in allowing you to interrupt someone else's actions, and you are, for whatever reason, playing a sub-game of clever wordings and rule by implication to try and forbid that.

The rules allow you to:

1. Set the criteria for a Readied action to anything you can perceive and react to.

2. Act immediately after those criteria are met, not "at the end of the Action in which those criteria are met."

Setting your reaction to eg. "when they reach for their spell component pouch" or, more generally, "when they start to cast a spell" isn't a clever wording game, it's using the reaction system, as written, for one of its straightforward purposes. I do think that the designers intended to reward player cleverness and smart usage of their abilities, of course, but this isn't even an odd or unusual application - and I feel your interpretation would be much more hostile to players.

What you are saying is that if a new player announces that they're going to ready an action to respond when someone begins to cast a spell (or reaches for their spell component pouch, if you want it to be more specific) - something that the rules unambiguously allow - you'll shut them down and say "no, stop trying to be clever." (With, and apologies if I'm misreading you, an undercurrent of hostility towards them for even attempting it - ie. a "that's not the sort of player I want at my table" vibe.)

I don't feel that that's how things should go. And, in fact, we have the designer themselves specifically stating that they would allow it, so... I don't know what you mean by implying that they wouldn't? Because we know for a fact that they would. You can, at best, argue that maybe that wasn't the default, but you can't argue that they wouldn't allow it at their table.

Basically I think you're taking this unnecessarily adversarial "don't let the players get away with anything" position, which is extremely toxic to good play and which penalizes players for using the rules as written in intelligent ways - especially, as in this case, where I think the rules as written clearly allow this, outside of a knee-jerk "no, that's TOO clever, it reeks of shenanigans." Treat your players as if they're trying to have fun within the game, not as if they're constantly trying to pull something that you need to take the hammer to.

Especially since - if you allow it, as a developer says you should and as a strict reading of the rules would allow, then that newer player in your example, the one you described as a "scrub?" They'll now know it's allowed and possible and will do it in the future. That's good! That's how players learn the game. More than that, they'll learn that D&D is a game about coming up with clever ideas rather than rigidly adhering to some mechanical concept of what the game "ought to" allow, ie. the rules are both flexible enough and durable enough to support clever ideas without breaking. As a DM, I'd much rather send the message that cleverness is rewarded and encouraged than the message that "you cannot get away with ANYTHING, just treat it as a computer game!"

This is the real reason why the dev allowed it above, of course. I don't know the full details of every thought they had when making the game, but I do think that, contrary to what you're saying, "cleverness" was absolutely something they wanted to reward and encourage, not something they wanted to discourage.

If something is "clever" in a way that completely breaks the game, sure, that's different; in that case, whether the rules-as-written allow it or not isn't important - you have to address it, either by banning it or tweaking it or whatever. But delaying a silence spell like this barely benefits the players even when it works, and comes with significant drawbacks (there's a risk of wasting it, and you could have just cast it earlier; all you get as a trade-off is casting it exactly where it's needed.) So I don't understand your hostility to it beyond a vague kneejerk sense that if you conceded that it's allowed, the players would be "getting away" with something. And I think that that is a really, really really bad way to approach rules questions for several reasons.

This is also why I particularly object to your "actions are atomic" insistence, which is nowhere in the rules, would make the rules worse at representing reality, would discourage clever actions that the rules otherwise allow, and which seems premised on generally treating the game like a machine rather than a story.

To get back to my "that's not the sort of player I want at my table" interpretation above, I feel the exact opposite - I would hate to play with a DM who interpreted things the way you are. Not so much for this specific example (which is relatively obscure) but the mindset I gather is behind it, which I feel makes for bad games. Whereas, as a DM, I would absolutely prefer the sort of players who explore the boundaries of the game and try to use the options available to them as cleverly as they can.

[DMThac0]

Making an Attack: Whether you’re striking with a melee weapon, firing a weapon at range, or making an attack roll as part of a spell, an attack has a simple structure.

1. Choose a target. Pick a target within your attack’s range: a creature, an object, or a location.
2. Determine modifiers. The DM determines whether the target has cover and whether you have advantage or disadvantage against the target. In addition, spells, special abilities, and other effects can apply penalties or bonuses to your attack roll.
3. Resolve the attack. You make the attack roll. On a hit, you roll damage, unless the particular attack has rules that specify otherwise. Some attacks cause special effects in addition to or instead of damage.




Ready
First, you decide what perceivable circumstance will trigger your reaction. Then, you choose the action you will take in response to that trigger, or you choose to move up to your speed in response to it.

(snip)

When the trigger occurs, you can either take your reaction right after the trigger finishes or ignore the trigger.

So, now we have the two situations quoted from the book: Making an Attack and Ready. It is defined in Making an Attack that Casting a Spell is covered by these rules.

---

Player declares a Ready Action with the trigger "When the Caster begins to cast their spell".
Caster declares the Attack Action (Cast Spell).

At this point in time it becomes important to follow the flow of the rules:

*I will assume the declaration of the Attack Action (Cast Spell) is the same as "When the Caster begins to cast their spell".

Resolution 1
The Ready Action is triggered because the Caster declared an Attack Action (Cast Spell).
The Caster has not completed their Attack Action as the 3rd step of Making an Attack has not occurred, the Attack Action (Cast Spell) is now resolved.

Resolution 2
The Caster resolves the spell according to Making an Attack step 3.
The Ready Action is triggered because the Caster declared an Attack Action (Cast Spell).

---

If you choose Resolution 1 then you are potentially making spells like Counterspell and abilities like the Monster Hunter Ranger's obsolete. This resolution allows anyone, with any tool, to potentially kill a caster before they finish their spell. Otherwise the spell will not be interrupted because the caster is not dead and, per the flow of Making an Attack, the spell must resolve.

If you choose Resolution 2 then you are going by the way that most people have interpreted the flow of combat. It gives the spells and abilities that specifically state they can interrupt a spell their time to shine.

Neither resolution nor the rules of combat can allow for a spell to be interrupted as the Making an Attack loop must be resolved in all 3 parts to be considered the use of the Attack Action.

[Aquillion]

If you choose Resolution 1 then you are potentially making spells like Counterspell and abilities like the Monster Hunter Ranger's obsolete. This resolution allows anyone, with any tool, to potentially kill a caster before they finish their spell. Otherwise the spell will not be interrupted because the caster is not dead and, per the flow of Making an Attack, the spell must resolve.Neither of the alternatives you mentioned require a Readied Action, which is a huge deal (you're sacrificing an entire action, and possibly getting nothing out of it if your criteria aren't met!)

Beyond that, I tend to agree that attacks can't interrupt spells (just because 5e doesn't actually have any rules to allow damage to disrupt casting.) But I'm arguing for eg. using Silence to prevent the completion of the verbal components, or dropping a Wall of Stone or other effect to block their line of sight. I think that that works.

Also note that readying a spell this way has even more costs than other readied actions - it takes concentration, which can break, and you actually waste the spell slot if the reaction doesn't go off. We can keep arguing RAW, although I think the arguments are circular at this point, and we can keep arguing RAI, although we have a Sage Advice quote saying they'd allow it; but I definitely don't see the argument that it's mechanically unbalanced.

Counterspell is faster (no wasted action on your part), less risky (no risk of wasting the spell unless you actually have to counter something), and affects a wider range of spells (each readied spell can only counter certain things - eg. verbal components for Silence or spells whose LOS you can block with Wall of Stone.) If the lich casts Finger of Death when you're not prepared for it, you can still counter him just fine; but you can't say "oh, wait, can we rewind to my turn so I can ready an action to silence that?"

Also, I feel like you misunderstand something:

Resolution 1
The Ready Action is triggered because the Caster declared an Attack Action (Cast Spell).
The Caster has not completed their Attack Action as the 3rd step of Making an Attack has not occurred, the Attack Action (Cast Spell) is now resolved.
No, no, no. That's not how Ready Actions work. "declared an Attack Action" isn't a thing in-universe. They respond to things you can perceive, not to abstract game concepts.

So a readied action for "when the lich starts to cast a spell" would go off when the lich did something that obviously indicated they were casting - reaching for their spell component pouch, say. (I think it's fair to argue that the trigger has to be more specific, which would make triggers even weaker - obviously if your trigger goes off when they reach for their spell component pouch, you will react only to spells with material components.)

But the basic idea is that actions are not atomic, robotic computer-game style things. They represent stuff you're doing in universe, and the rules recognize this and allow you to take advantage of that via mechanics like reactions. The lich, in-universe, doesn't just get to say "I AM CASTING A SPELL AND NOW MOVE ON TO STEP 1 OF THE PROCESS, BEEP BOOP." In-universe, they have to perform certain actions as part of that spell - the process merely provides the way to quickly adjudicate that. And those actions still exist and matter and can trigger other rules - they're not just meaningless fluff like an animation in a computer game.

The fact that eg. casting a spell with a material component requires reaching for your component pouch means that if you try to do so, you'll trigger any reactions keyed off of that action before your spell is finished.

[DMThac0]

So, if I am to understand you correctly:


I am playing a Fighter, I am currently wielding a crossbow, and I state that I ready an action that "If any opponent starts any form of attack or spell toward my party I shoot them".

A
The next opponent that declares a Spell I can then shoot before their action is taken and it interrupts them from taking that action, thus preventing the spell?

or

B
The next opponent that declares a weapon attack I can than shoot before their action is taken and it interrupts them from taking that action, thus preventing that attack?

--

Both are using the same method as the Resolution 1 I offered, both are considered interrupting the opponent, and both use a Ready with the trigger word "starts".

[Rukelnikov]

So, if I am to understand you correctly:


I am playing a Fighter, I am currently wielding a crossbow, and I state that I ready an action that "If any opponent starts any form of attack toward my party I shoot them".

A
The next opponent that declares a Spell I can then shoot before their action is taken and it interrupts them from taking that action, thus preventing the spell?

or

B
The next opponent that declares a weapon attack I can than shoot before their action is taken and it interrupts them from taking that action, thus preventing that attack?

--

Both are using the same method as the Resolution 1 I offered, both are considered interrupting the opponent, and both use a Ready with the trigger word "starts".

You can do both, and neither would stop the action from taking place after your shot (unless you drop them)

[DMThac0]

You can do both, and neither would stop the action from taking place after your shot (unless you drop them)

That is my understanding, I'm trying to understand Aquillion's point of view better.

[Aquillion]

So, if I am to understand you correctly:


I am playing a Fighter, I am currently wielding a crossbow, and I state that I ready an action that "If any opponent starts any form of attack or spell toward my party I shoot them".

A
The next opponent that declares a Spell I can then shoot before their action is taken and it interrupts them from taking that action, thus preventing the spell?

or

B
The next opponent that declares a weapon attack I can than shoot before their action is taken and it interrupts them from taking that action, thus preventing that attack?Ideally I think I would prefer that the readied action be described in slightly more in-universe terms ("raising their weapons towards us", "move to attack us", etc.)

More importantly, in all the examples you gave, while I think you can interrupt them, it doesn't prevent anything (unless you kill them.) Nothing about damage inherently interrupts anything or prevents anything.

Now, if you had a feature that let you knock them back when you hit them or otherwise had some effect beyond just damage, that might prevent some stuff. But not just hitting them, no. As I said repeatedly above, 5e doesn't have concentration checks just to cast spells, and there's no particular reason to think hitting someone would ruin their attack.

(A very generous DM might have it give them disadvantage or something, which is a reasonable interpretation. But they're not required to do so and it would just be an ad-hoc ruling, since advantage / disadvantage is sometimes an intentionally vague DM-call thing that can come from almost anywhere.)

[Rukelnikov]

That is my understanding, I'm trying to understand Aquillion's point of view better.

If instead of an attack you readied Silence, you could cast it on the area around the enemy caster and thus prevent the spell from being cast (if it includes a verbal component)

[Aquillion]

If instead of an attack you readied Silence, you could cast it on the area around the enemy caster and thus prevent the spell from being cast (if it includes a verbal component)Yes. Note that doing so has a substantially higher risk and cost (you could lose the spell if you get hit yourself before it goes off, since holding a Readied spell does require concentration; and if they don't trigger your reaction, your spell is wasted.)

Hmm... you know, I never really considered the advantages of readied-action Minor Illusion before. You can do a lot with that.

[Rukelnikov]

Yes. Note that doing so has a substantially higher risk and cost (you could lose the spell if you get hit yourself before it goes off, since holding a Readied spell does require concentration; and if they don't trigger your reaction, your spell is wasted.)

And most importantly, it prevents maintaining concentration on a different spell, since readying a spell means concentrating on it.

[DMThac0]

Ideally I think I would prefer that the readied action be described in slightly more in-universe terms ("raising their weapons towards us", etc.)

More importantly, in all the examples you gave, while I think you can interrupt them, it doesn't prevent anything (unless you kill them.) Nothing about damage inherently interrupts anything or prevents anything.

Now, if you had a feature that let you knock them back when you hit them or otherwise had some effect beyond just damage, that might prevent some stuff. But not just hitting them, no. As I said repeatedly above, 5e doesn't have concentration checks just to cast spells, and there's no particular reason to think hitting someone would ruin their attack.

(A very generous DM might have it give them disadvantage or something, which is a reasonable interpretation. But they're not required to do so and it would just be an ad-hoc ruling, since advantage / disadvantage is sometimes an intentionally vague DM-call thing that can come from almost anywhere.)

This becomes a very treacherous path to take in my mind. As a caster I could ready Hold Person for the moment a creature bears down on my party to attack. Let's say this happens on the first round and the creature fails the save. The entire round is now given to the players with the getting advantage on attacks. One of the players does something else to pin the creature down on their turn. I then ready my action to Hold Person again. It is quite possible to lock an opponent out without them ever getting a chance to swing once. It's also possible to reverse this and do the same to the player(s).

As a DM, that situation would make me very frustrated, as a player it would make me very bored. However, as is always the case, to each their own, your table, your fun.

[Max_Killjoy]

I understand that you think that there is some meaningful way to finish starting to cast a spell while you're still casting the spell. In the absence of any distinct phases of spell casting, I don't find that convincing.

It's a matter of very precise wording, and whether that matters, and whether one allows it.

Their proposed trigger isn't "casts a spell", it's "starts casting a spell", so it's instantaneous, and finishes at the same instant it starts.

[Aquillion]

This becomes a very treacherous path to take in my mind. As a caster I could ready Hold Person for the moment a creature bears down on my party to attack.
Note that this one is unambiguously allowed under the rules (you're reacting to movement, not an attack, meaning that it's identical to the "trapdoor switch" given as an example in the Ready Action rules.) As far as I can tell, none of the arguments above would support preventing your player from using Hold Person that way.

However, it's not nearly as powerful as you seem to think, because...


Let's say this happens on the first round and the creature fails the save. The entire round is now given to the players with the getting advantage on attacks. One of the players does something else to pin the creature down on their turn. I then ready my action to Hold Person again. It is quite possible to lock an opponent out without them ever getting a chance to swing once. It's also possible to reverse this and do the same to the player(s).
...how is that any different than casting Hold Person normally? Note that the save to break free of Hold Person is made at the end of their turn, not the beginning (ie. you don't get to act on the turn in which you make the save), meaning that you can just Hold Person them again and again as long as you have spell slots without the need for a readied action. In fact, readying an action for that is a terrible idea, since if they fail the save then your spell slot is wasted... but, again, you don't even need that because once they make the save, you're going to get an action before they do either way, and can just use that action to try and Hold Person them again.

If you have a chance to ready an action, then you had a chance to Hold Person them during your turn, without the Readied action. There's only a few situations where the Ready Action here actually helps:

1. You weren't sure if the creature was going to move towards you at all (but in this case, you waste the spell slot if they don't, or even if they just wait a round before doing so.)

2. The creature was too far away for you to hit with Hold Person, and you Ready an action to hold them when they move into range.

3. You want to hold the creature in a particular spot (ie. where the rest of your party can easily reach it), and are holding your action until they reach that spot.

Those aren't particularly exploitive usages, and they're both clearly allowed; all of them also risk wasting your spell if the creature does something unexpected or just holds back and doesn't trigger your reaction.

The "frustration" you're referring to here comes from the power of Hold Person, not readied actions.

[Coffee_Dragon]

One of the two examples given for readying an action is "an interrupt", as you put it, how can you then say that the "deafult" is non-interruption?

DMG 252 could not be any more clear when it says a) reactions may specify they interrupt, and b) otherwise, they do not.

The example of movement can be complicated to require additional adjudication, but in the basic case of the trigger being someone moving into an area, and that someone moving into that area, and the reaction happening after that someone has moved into that area, seems like a case of non-interruption and doesn't cause me to reevaluate the default.


the mindset I gather is behind it, which I feel makes for bad games

Sorry, I'm not taking this bait.

[Rukelnikov]

DMG 252 could not be any more clear when it says a) reactions may specify they interrupt, and b) otherwise, they do not.

"If a reaction has no timing specified, or the timing is unclear, the reaction occurs after its trigger finishes, as in the Ready action."

If you are reffering to this, then it doesn't say what you think it does. My trigger is "when X starts to cast a spell", as soon as he starts the trigger is finished, the action is not.


The example of movement can be complicated to require additional adjudication, but in the basic case of the trigger being someone moving into an area, and that someone moving into that area, and the reaction happening after that someone has moved into that area, seems like a case of non-interruption and doesn't cause me to reevaluate the default.

PC: "I will pull the lever when he steps on square X"
Enemy: "I move from Square A to Square B"

[PC][B][X][A]

Clearly interrupting enemy movement.

[Coffee_Dragon]

If you are reffering to this, then it doesn't say what you think it does. My trigger is "when X starts to cast a spell", as soon as he starts the trigger is finished, the action is not.

As I've said, it would be a bizarre way to design if they meant, "There are some reactions that interrupt, and then there's the rest, including Ready. Ready also interrupts!" I don't think we're getting any further here.


PC: "I will pull the lever when he steps on square X"
Enemy: "I move from Square A to Square B"

[PC][B][X][A]

Clearly interrupting enemy movement.

Movement is incremental in a way that actions (typically) are not. I have already admitted the case can be complicated to the point where you are interrupting something, but in the basic case as described, it isn't movement.

[Rukelnikov]

I don't think we're getting any further here.

Yup, agreed

[MaXenzie]

In regards to a readied action, I believe the specific wording is important.

"I ready an action to cast hold person when the mage casts a spell" will allow the enemy mage to cast a spell before the hold person activates.

"I ready an action to cast hold person once the mage begins to cast a spell" will let the mage waste a spell slot and then get held, as the trigger was them beginning to cast a spell, but specifically not them casting it.

Wording is important, folks.

[Tanarii]

The ready action description gives us two examples of its use, one of them is literally interrupting another creatures movement:

"lf lhe cultist steps on the trapdoor, I'll pull the lever that opens it"
That's not an interruption. It's an after the trigger is completed reaction.

Keep in mind movement is not an action in this edition. It is not indivisible by default.

[TheUser]

In regards to a readied action, I believe the specific wording is important.

"I ready an action to cast hold person when the mage casts a spell" will allow the enemy mage to cast a spell before the hold person activates.

"I ready an action to cast hold person once the mage begins to cast a spell" will let the mage waste a spell slot and then get held, as the trigger was them beginning to cast a spell, but specifically not them casting it.

Wording is important, folks.

The slot wouldn't be wasted; because they failed to provide the components for the spell it never gets cast and hence the slot is not used; whereas counter spell says the spell just fails (as opposed to fails to cast).

[MaXenzie]

The slot wouldn't be wasted; because they failed to provide the components for the spell it never gets cast and hence the slot is not used; whereas counter spell says the spell just fails (as opposed to fails to cast).

That depends on your definition of "beginning" to cast a spell.

Since they have finished beginning to cast a spell, they are in the process of casting it. Meaning the components have been used and arcane energy is swirling and magic is forming, etc, etc.

[JackPhoenix]

That depends on your definition of "beginning" to cast a spell.

Since they have finished beginning to cast a spell, they are in the process of casting it. Meaning the components have been used and arcane energy is swirling and magic is forming, etc, etc.

And once that happens, the spell is cast. There's no distinction between "beginning to cast a spell" and "cast a spell" in the rules, unless the spell has a casting time longer than one action.

They can't finish an act that doesn't exist.

[tieren]

PC: "I will pull the lever when he steps on square X"
Enemy: "I move from Square A to Square B"

[PC][B][X][A]

Clearly interrupting enemy movement.

I think this is a key misunderstanding in the interrupt debate.

On the one hand yes the enemy's attempt to move all the way to B is interrupted, but his movement on the square x was not.

a closer analogy to interrupting spell casting would be:

PC: "I will repelling blast him back when he starts to enter square X"

The question then being, does the enemy move onto X and get blasted back (presumably) or does he raise his foot like he is about to step into X and then gets blasted back without ever stepping on X. That is the question of whether his movement was interrupted mid step rather than interrupted in the sense of not reaching his final intended destination.

I am ok with readying an action to key off a perceivable phenomenon (waving hands, speaking, etc...) and having the readied action take place before the spell is cast.

Now in the case of a readied silence spell. If the caster hadn't used their movement yet I would let them walk out of the area of effect before finishing their spell (space allowing); same with most line of sight obstructions.

Heres one:

Caster A readies shocking grasp for when Caster B starts to cast a spell; Caster B starts to cast fireball, Caster A starts to cast shocking grasp, Caster B then actually casts counterspell on the shocking grasp.

or how about readying an attack to strike when the Caster "begins" to cast the shield spell.

Thug A readies attack, Thug B swings at Caster, Caster "begins" to cast shield, triggering Thug A's attack.

If Thug A's attack happens before the spell is done being cast it seems to counter the point of the shield spell being faster than attacks and preventing them.

[Telok]

Additional issue with equating movement and spellcasting: Not all tables use a mat & minis.

[Rukelnikov]

That's not an interruption. It's an after the trigger is completed reaction.

Keep in mind movement is not an action in this edition. It is not indivisible by default.

Ok, I can get that.


I think this is a key misunderstanding in the interrupt debate.

On the one hand yes the enemy's attempt to move all the way to B is interrupted, but his movement on the square x was not.

a closer analogy to interrupting spell casting would be:

PC: "I will repelling blast him back when he starts to enter square X"

The question then being, does the enemy move onto X and get blasted back (presumably) or does he raise his foot like he is about to step into X and then gets blasted back without ever stepping on X. That is the question of whether his movement was interrupted mid step rather than interrupted in the sense of not reaching his final intended destination.

Guess it depends on the trigger, "When he's about to step on square X" would trigger before he actually stepped in it, "When he steps on Square X" would be once he has set a foot on it. I don't really know what "starting to enter a square" would mean, or if it is even a perceivable circumstance, which is the only constraint for choosing triggers.


I am ok with readying an action to key off a perceivable phenomenon (waving hands, speaking, etc...) and having the readied action take place before the spell is cast.

Now in the case of a readied silence spell. If the caster hadn't used their movement yet I would let them walk out of the area of effect before finishing their spell (space allowing); same with most line of sight obstructions.

Heres one:

Caster A readies shocking grasp for when Caster B starts to cast a spell; Caster B starts to cast fireball, Caster A starts to cast shocking grasp, Caster B then actually casts counterspell on the shocking grasp.

or how about readying an attack to strike when the Caster "begins" to cast the shield spell.

Thug A readies attack, Thug B swings at Caster, Caster "begins" to cast shield, triggering Thug A's attack.

If Thug A's attack happens before the spell is done being cast it seems to counter the point of the shield spell being faster than attacks and preventing them.

Its an interesting case for sure, my stance would have to interpret it as Thug A's attack would target an AC without Shield, Thug B's attacks would have shield applied against them.

Consider this case now:

5th lvl wizard readies action to launch a crossbow bolt at an enemy spellcaster when its starts to cast a spell.

Enemy spellcaster declares casting of Wall of Fire.

5th Wiz realizes enemy spellcaster is doing the components for some spell, he can cast Counterspell to disrupt it, but he cannot pull the trigger?

[TheUser]

And once that happens, the spell is cast. There's no distinction between "beginning to cast a spell" and "cast a spell" in the rules, unless the spell has a casting time longer than one action.

They can't finish an act that doesn't exist.

I mean...by virtue of the fact that counterspell occurs DURING A CAST would seem to indicate that if you went immediately from casting to being finished casting there is no window of opportunity to counter it....and yet counter spell describes inside the ruleset, a window of opportunity between starting and finishing a spell cast.

If you stop a character from providing all the components of a spell -even during the process of casting- the spell does not go off and the spell slot is not used. Counterspell dictates specifically that the spell finishes but instead fails.

[CorporateSlave]

Five pages to read through! Hope I haven't missed something and am just repeating!

First of all, I agree and disagree with everyone.

Clearly there are Reactions that interrupt - even a sword attack - by design, but I don't know that there is any RAW to support being able to disrupt a spell being cast with a Readied physical Attack. In fact, didn't this used to be a feature of earlier editions of D&D that is no longer present in 5e? (could be wrong about this, admittedly)

How to interrupt a sword attack before it is resolved - Protection fighting style (or a few other things that impose Disadvantage). These Reactions trigger when an Attack is made, but before the dice rolling is resolved...as it changes how many dice are rolled (you have to declare its use before the dice roll is known, in any case).

However, this is a specific dedicated Reaction ability, not using a Reaction to pop off a Readied Action, and by the RAW, we know specific trumps general.

There are clearly certain specific abilities that "interrupt" spells, but are they really specific exceptions (I think probably yes)? Counterspell for example, is also a dedicated Reaction, not a Readied Action.

Most of the RAW I have seen does not make any specific examples of how Readied Actions can interrupt Actions, only Movement. But everything can interrupt Movement. You can interrupt your own Movement to Move, Cast A Spell, Move. In a lot of ways, "Movement" is more a group of discrete 5' increments and less one unified activity such like an Action. Besides, per the PHB RAW Movement and Actions are explicitly different things. The Ready Action itself differentiates between Actions and Movement. (it may be of some significance to notice that it is the Ready Action, not "Readying an Action." You can use the Ready Action to trigger either an Action or Movement as your Reaction)

Few people would argue that you could not specify a trigger of "If that Orc takes one step closer to us, I'm going to Attack it with my longbow" and when the Orc closes from 30' away to 25' away you get your shot. But that's Movement interrupted (maybe interrupted, for all anyone knows the orc may only have been intending to move 5' closer), it's not their Action interrupted, and per 5e, RAW, those are two very different things. To imply that the ability to interrupt full potential Movement also means you can interrupt something else entirely, an Action, is just that...a subjective implication that is not supported in the rules. There is no RAW stating an Action and Movement are the same thing. They are entirely different sections in the PHB, in fact.

If I were DM'ing, I would probably not allow the cheese of a PC stating "I Ready an Attack for the moment I see the caster start to cast a spell, then shoot him to interrupt it and force a Concentration check (or otherwise cause it to fail). There are things that per RAW can interrupt or otherwise cancel out a spell. Older editions included attacks/taking damage in this, 5e does not. The fact that there are specific examples/abilities that interrupt or cancel spells yet no description of how to use a Readied Attack Action to do the same really makes me thing that those are Specific examples that beat the General rule that a Readied Attack Action will only occur once the entirety of the trigger is completed, and specifying a trigger of starting to do something, particularly an Action, does not suffice.

The particular wording can currently be rules lawyered perhaps, but maybe the simplest way to explain my view:

There is no general RAW for interrupting spells being cast with a casting time of 1 Action or less. This would have been terribly easy to include in the rules if it was intended by the game designers. It was not included. "Common sense" arguments can be made, but the only RAW general rule relating to Casting a Spell that discusses maintaining any type of Concentration to Cast a Spell concerns spells with a casting time of greater than 1 Action...or using the Ready Action to Cast and Hold the spell.

There are many specific RAW ways to interrupt spells being cast. These specific examples (spells/abilities) beat the general rule that a Readied Action must wait until after the trigger resolves to take place. Simply gaming the system by using tricky wording that attempts to break down an Action into discrete steps that allow for interruption is some fine power gaming, but not something I feel a reasonable DM should allow, and not something RAW specifically states you can do.

[DMThac0]

I mean...by virtue of the fact that counterspell occurs DURING A CAST would seem to indicate that if you went immediately from casting to being finished casting there is no window of opportunity to counter it....and yet counter spell describes inside the ruleset, a window of opportunity between starting and finishing a spell cast.

If you stop a character from providing all the components of a spell -even during the process of casting- the spell does not go off and the spell slot is not used. Counterspell dictates specifically that the spell finishes but instead fails.

This is a case of specific beats general. Counterspell specifically states that it interrupts the spell, where as none of the other actions suggested (aside from the one Ranger subclass) have that specification. That makes the Counterspell unique in this ability not the rule.

[Man_Over_Game]

Five pages to read through! Hope I haven't missed something and am just repeating!

First of all, I agree and disagree with everyone.

Clearly there are Reactions that interrupt - even a sword attack - by design, but I don't know that there is any RAW to support being able to disrupt a spell being cast with a Readied physical Attack. In fact, didn't this used to be a feature of earlier editions of D&D that is no longer present in 5e? (could be wrong about this, admittedly)

How to interrupt a sword attack before it is resolved - Protection fighting style (or a few other things that impose Disadvantage). These Reactions trigger when an Attack is made, but before the dice rolling is resolved...as it changes how many dice are rolled (you have to declare its use before the dice roll is known, in any case).

However, this is a specific dedicated Reaction ability, not using a Reaction to pop off a Readied Action, and by the RAW, we know specific trumps general.

There are clearly certain specific abilities that "interrupt" spells, but are they really specific exceptions (I think probably yes)? Counterspell for example, is also a dedicated Reaction, not a Readied Action.

Most of the RAW I have seen does not make any specific examples of how Readied Actions can interrupt Actions, only Movement. But everything can interrupt Movement. You can interrupt your own Movement to Move, Cast A Spell, Move. In a lot of ways, "Movement" is more a group of discrete 5' increments and less one unified activity such like an Action. Besides, per the PHB RAW Movement and Actions are explicitly different things. The Ready Action itself differentiates between Actions and Movement. (it may be of some significance to notice that it is the Ready Action, not "Readying an Action." You can use the Ready Action to trigger either an Action or Movement as your Reaction)

Few people would argue that you could not specify a trigger of "If that Orc takes one step closer to us, I'm going to Attack it with my longbow" and when the Orc closes from 30' away to 25' away you get your shot. But that's Movement interrupted (maybe interrupted, for all anyone knows the orc may only have been intending to move 5' closer), it's not their Action interrupted, and per 5e, RAW, those are two very different things. To imply that the ability to interrupt full potential Movement also means you can interrupt something else entirely, an Action, is just that...a subjective implication that is not supported in the rules. There is no RAW stating an Action and Movement are the same thing. They are entirely different sections in the PHB, in fact.

If I were DM'ing, I would probably not allow the cheese of a PC stating "I Ready an Attack for the moment I see the caster start to cast a spell, then shoot him to interrupt it and force a Concentration check (or otherwise cause it to fail). There are things that per RAW can interrupt or otherwise cancel out a spell. Older editions included attacks/taking damage in this, 5e does not. The fact that there are specific examples/abilities that interrupt or cancel spells yet no description of how to use a Readied Attack Action to do the same really makes me thing that those are Specific examples that beat the General rule that a Readied Attack Action will only occur once the entirety of the trigger is completed, and specifying a trigger of starting to do something, particularly an Action, does not suffice.

The particular wording can currently be rules lawyered perhaps, but maybe the simplest way to explain my view:

There is no general RAW for interrupting spells being cast with a casting time of 1 Action or less. This would have been terribly easy to include in the rules if it was intended by the game designers. It was not included. "Common sense" arguments can be made, but the only RAW general rule relating to Casting a Spell that discusses maintaining any type of Concentration to Cast a Spell concerns spells with a casting time of greater than 1 Action...or using the Ready Action to Cast and Hold the spell.

There are many specific RAW ways to interrupt spells being cast. These specific examples (spells/abilities) beat the general rule that a Readied Action must wait until after the trigger resolves to take place. Simply gaming the system by using tricky wording that attempts to break down an Action into discrete steps that allow for interruption is some fine power gaming, but not something I feel a reasonable DM should allow, and not something RAW specifically states you can do.

I agree with everything you said.

5e was intended to fix the problems of the past, and there were two big problems that people had with 3.5:

Magic was far too strong, and a mage was useless when he didn't have magic to make him OP.

So they made magic much weaker, but then ramped up the reliability of mages to compensate. Now a Fighter can be on the same level as a Wizard (at least, in comparison to 3.5), but they had to remove all the finicky parts of magery to make sure that mages still felt valid. It's a balancing act.

Now, I don't have a major problem if someone takes some kind of risk/resource to prevent a mage from casting a spell, but it shouldn't be reliable.

[tieren]

Consider this case now:

5th lvl wizard readies action to launch a crossbow bolt at an enemy spellcaster when its starts to cast a spell.

Enemy spellcaster declares casting of Wall of Fire.

5th Wiz realizes enemy spellcaster is doing the components for some spell, he can cast Counterspell to disrupt it, but he cannot pull the trigger?

Personally I don't have a problem with the readied attack occurring before the spell completes (although at my table a more specific trigger would be required), I don't agree with the idea that the attack somehow disrupts the casting, after the crossbow attack is resolved the enemy casts his firewall (assuming they survived the attack)

[stoutstien]

Personally I don't have a problem with the readied attack occurring before the spell completes (although at my table a more specific trigger would be required), I don't agree with the idea that the attack somehow disrupts the casting, after the crossbow attack is resolved the enemy casts his firewall (assuming they survived the attack)
Second this.
now if the Castor was casting a long-term spell that required concentration and the reaction was an attempt to disrupt that I see no problem. Using the firewall example it may not be possible due to lose of line of sight.Trading action/reaction for a chance to end a spell early seems balanced.
Which remind me how bad the mage Slayer feat is as written.

[Contrast]

Consider this case now:

5th lvl wizard readies action to launch a crossbow bolt at an enemy spellcaster when its starts to cast a spell.

Enemy spellcaster declares casting of Wall of Fire.

5th Wiz realizes enemy spellcaster is doing the components for some spell, he can cast Counterspell to disrupt it, but he cannot pull the trigger?

Its also worth just reiterating that this is a game.

Why is a character capable to perfectly jumping the exact same distance every time? Why can only level 20 dex based character whose focused on training with a bow attack 8 times in a round (a fighter) while another can only attack once (a rogue)? Why does a rogue always strike for substantial damage only when he's hidden or an enemy is standing next to his opponent, can't he get lucky? Why do PCs sit there and watch enemies stab their unconscious friend, only leaping into action when its their 'turn'?

The answer to all these things is nothing to do with logic and everything to do with the type of game 5E wants to be. So the reason you can counter a spell with Counterspell and not with a crossbow is nothing to do with the timing and mechanics of firing a crossbow bolt at a man in a funny hat in the real world and everything to do with the fact that we're looking up the rules for Readying an Action in a RulebookTM.

A Counterspell can interrupt because the rules says it can. A Readied action triggers when the triggering action finishes because the rules say it does. Obv you don't have to play it that way in your living room (I usually wouldn't allow it to interrupt but would probably allow exceptions depending on circumstance), I ain't the boss of you :smalltongue:

[JackPhoenix]

Why can only level 20 dex based character whose focused on training with a bow attack 8 times in a round (a fighter) while another can only attack once (a rogue)?

Because one focuses his training on speed, while the other focuses more on accuracy.


Why does a rogue always strike for substantial damage only when he's hidden or an enemy is standing next to his opponent, can't he get lucky?

He can. It's called critical hit. Also, he could have any other source of advantage than being hidden, or be a swashbuckler.


Why do PCs sit there and watch enemies stab their unconscious friend, only leaping into action when its their 'turn'?

They don't. Turns and rounds only exist for the player's convenience, in fiction, the actions are simultaneous.

[Rukelnikov]

Personally I don't have a problem with the readied attack occurring before the spell completes (although at my table a more specific trigger would be required), I don't agree with the idea that the attack somehow disrupts the casting, after the crossbow attack is resolved the enemy casts his firewall (assuming they survived the attack)

But, I'm in favor of that, damage doesn't prevent/disrupt the spell in any way (unless it drops the caster)

[Rukelnikov]

Why is a character capable to perfectly jumping the exact same distance every time? Why can only level 20 dex based character whose focused on training with a bow attack 8 times in a round (a fighter) while another can only attack once (a rogue)? Why does a rogue always strike for substantial damage only when he's hidden or an enemy is standing next to his opponent, can't he get lucky? Why do PCs sit there and watch enemies stab their unconscious friend, only leaping into action when its their 'turn'?

There's an in world logic for all of those, fortunately JP covered most of them already.


The answer to all these things is nothing to do with logic and everything to do with the type of game 5E wants to be. So the reason you can counter a spell with Counterspell and not with a crossbow is nothing to do with the timing and mechanics of firing a crossbow bolt at a man in a funny hat in the real world and everything to do with the fact that we're looking up the rules for Readying an Action in a RulebookTM.

Exactly, the rules say "you decide what perceivable circumstance will trigger your reaction.". If I can perceive the casting of a spell well enough to counter it, then it is a perceivable circumstance, and thus a valid trigger for Ready Action.


A Counterspell can interrupt because the rules says it can. A Readied action triggers when the triggering action finishes because the rules say it does. Obv you don't have to play it that way in your living room (I usually wouldn't allow it to interrupt but would probably allow exceptions depending on circumstance), I ain't the boss of you :smalltongue:

Nope, rules don't say that. You don't need to specify an Action as the trigger, you can define any perceivable circumstance as the trigger, and your ready action comes after the trigger has finished.

[ProsecutorGodot]

Nope, rules don't say that. You don't need to specify an Action as the trigger, you can define any perceivable circumstance as the trigger, and your ready action comes after the trigger has finished.

If we're nitpicking "triggering action" to mean "literally an action" for no reason then the discussion has gone far enough off the rails that we might as well just agree to disagree. Does it really matter to specify that it doesn't have to be an action if the point was that the reaction occurs after the trigger, whether it was an action or not?

There's no way for your character to be acutely aware in world of what "beginning to cast a spell" looks like in a form that could be pre-empted by an arrow compared to "casting a spell" in a way that has become inevitable unless interrupted by appropriate magic like counterspell.

I'll advocate for case by case basis, such as a spellcasters duel where creative applications of magic could be used to interrupt a caster or using Silence specifically in response to a spellcasting. These seem like reasonable exceptions to make. What doesn't seem reasonable is creating a phase of spellcasting that doesn't exist to allow weapons to serve the same purpose.

If you're trying to stop a spellcaster from doing something, use your action. What exactly is even gained by trying to lawyer your readied attack when you could have reasonably (in the cases that a spellcaster is trying to cast a spell in your range) attacked them instead?

EDIT: Just as an example.
DM: "While your ally dispatches yet another one of the bandits, the robed one in the back begins erratically waving his arms around and speaking in a way that you don't understand"
P: "Does this trigger my readied action to shoot him as beginning to cast a spell?
DM: "This does look similar to what party Wizard does when he casts a spell, you can choose to respond if you would like."
P: "Okay, I shoot him"
DM: "As the words "wait don't shoot, I surrend-" finally break through his frantic babbling, your arrow hits him straight in the neck and he falls over dead"
P: "But I thought you said he was casting a spell, I wouldn't want to kill a man who was surrendering."
DM : "You thought he was casting a spell, but since you used your reaction to fire an arrow and not to attempt to identify that it was actually a spell you've instead shot a man trying desperately to dissuade you from killing all of his friends and him. You know he wasn't exactly a law-abiding citizen so it's not as if you've killed an innocent in this. Decide for yourself if this weighs heavily on you."

[CorporateSlave]

What doesn't seem reasonable is creating a phase of spellcasting that doesn't exist to allow weapons to serve the same purpose.

This, I suppose.

If the game designers had wanted a spell to be cast in "parts" that lent it to easy disruption (which is what we are talking about here lets face it...allowing any Ready Action trigger to disrupt a spell makes it insanely easy to counter anything but a Subtle Spell), they could easily have added those rules. Where are they? Well, in the part about spells with a casting time greater than one Action, sort of. That casting is broken down into parts...so to speak. But only that extended duration of casting.

As a DM I would not for one second buy the argument...which has zero RAW support...that a viable trigger for a Ready Action's Reaction use is "starting to cast a spell," outside of saying, ok, so your Reaction goes off as soon as the spell is cast, which is pretty clearly the RAI...but the spell is still cast, not interrupted.

Just because something doesn't have any particular RAW contradiction/forbiddance doesn't make it "according to the rules."

Spells with a casting time of 1 Action, 1 Bonus Action, or 1 Reaction simply are not divided up by RAW into any meaningful "phases" such as "beginning to cast, casting, finished casting." However, there are specific things that are able to interrupt. This tells me the RAI is that only these specific things can interrupt the casting. Everything else waits until the spell is cast.

[Kane0]

If you're trying to stop a spellcaster from doing something, use your action. What exactly is even gained by trying to lawyer your readied attack when you could have reasonably (in the cases that a spellcaster is trying to cast a spell in your range) attacked them instead?

EDIT: Just as an example.
DM: "While your ally dispatches yet another one of the bandits, the robed one in the back begins erratically waving his arms around and speaking in a way that you don't understand"
P: "Does this trigger my readied action to shoot him as beginning to cast a spell?
DM: "This does look similar to what party Wizard does when he casts a spell, you can choose to respond if you would like."
P: "Okay, I shoot him"
DM: "As the words "wait don't shoot, I surrend-" finally break through his frantic babbling, your arrow hits him straight in the neck and he falls over dead"
P: "But I thought you said he was casting a spell, I wouldn't want to kill a man who was surrendering."
DM : "You thought he was casting a spell, but since you used your reaction to fire an arrow and not to attempt to identify that it was actually a spell you've instead shot a man trying desperately to dissuade you from killing all of his friends and him. You know he wasn't exactly a law-abiding citizen so it's not as if you've killed an innocent in this. Decide for yourself if this weighs heavily on you."

Because you (the PC) doesn't want to be the first to act in a hostile manner but won initiative? And to me that sounds more like the DM screwing with you really. I would literally be like 'dude, is he casting a spell or not?'

[JoeJ]

Because you (the PC) doesn't want to be the first to act in a hostile manner but won initiative? And to me that sounds more like the DM screwing with you really. I would literally be like 'dude, is he casting a spell or not?'

Initiative is rolled at the beginning of combat. Why would you not want to act in a hostile manner in combat?

[ProsecutorGodot]

Because you (the PC) doesn't want to be the first to act in a hostile manner but won initiative? And to me that sounds more like the DM screwing with you really. I would literally be like 'dude, is he casting a spell or not?'

And I would ask you to make a check to see if you can recognize a spell or not, your PC doesn't have the knowledge of you as a player, he sees a robed man waving his hands around and practically screaming out unintelligible words. You would be told either "you've spent enough time with party wizard (or are party wizard) to recognize that these sounds and motions are completely unconventional for typical magic casting, you are confident that he's not actually casting a spell" on a success or "With as hectic as this fight has been, and the fact that you have seen him casting magic before, you can't be sure if this is a spell you haven't seen before or a bluff." on a failure.

If your trigger is trying to pre-empt the result of those actions, you don't get to know the result before you react.

Which is why I'm against the idea that you could set this type trigger in most cases*, it's metagamey and relies far too much on the structure of the game rules to define your in world actions and not enough on the potential realism of the scenario you're in.
*except in the cases where your readied action would reasonably be able to pre-empt the expected trigger without breaking the established chain of events, such as casting Silence instead of shooting an arrow.

[Rukelnikov]

And I would ask you to make a check to see if you can recognize a spell or not, your PC doesn't have the knowledge of you as a player, he sees a robed man waving his hands around and practically screaming out unintelligible words. You would be told either "you've spent enough time with party wizard (or are party wizard) to recognize that these sounds and motions are completely unconventional for typical magic casting, you are confident that he's not actually casting a spell" on a success or "With as hectic as this fight has been, and the fact that you have seen him casting magic before, you can't be sure if this is a spell you haven't seen before or a bluff." on a failure.

If your trigger is trying to pre-empt the result of those actions, you don't get to know the result before you react.

Which is why I'm against the idea that you could set this type trigger in most cases*, it's metagamey and relies far too much on the structure of the game and not enough on the potential realism of the scenario you're in.
*except in the cases where your readied action would reasonably be able to pre-empt the expected trigger without breaking the established chain of events, such as casting Silence instead of shooting an arrow.

If you can recognize the signs well enough to cast counterspell, you can recognize them well enough for it to be the trigger of a readied action.

[CorporateSlave]

Because you (the PC) doesn't want to be the first to act in a hostile manner but won initiative? And to me that sounds more like the DM screwing with you really. I would literally be like 'dude, is he casting a spell or not?'

I think more the point he is trying to make is; this is how screwy making up phases of spell casting can be. A player creating a trigger by imagining up something outside the rules such as "when he starts casting a spell" probably deserves to have a DM rules lawyer him right back. After all, does the fighter have time to make an Arcana check to figure out if a spell is definitely being cast? That probably ought to be an Action in and of itself...

And we haven't even touched on the fact that so far we've only discussed spells with a casting time of 1 Action. Is that going to be your trigger? "When the enemy wizards starts casting a spell with a casting time of one Action?" A bit Meta isn't it? A wizard casting a spell with a Reaction is still casting a spell aren't they? Yet the PHB describes a spell with a casting time of 1 Reaction as taking only a fraction of a second to cast.

How exactly do you justify with a "common sense" argument that this can be detected and interrupted in time(by anything that doesn't specify it actually can, such as the CounterSpell Spell)? Probably the reason the game designers only sub-divided spells with a casting time of greater than 1 Action...


If you can recognize the signs well enough to cast counterspell, you can recognize them well enough for it to be the trigger of a readied action.

The problem is, this is an extrapolation to general from a specific exception, which is the exact opposite of how 5e is supposed to work. (PHB Introduction, specific beats general) You've turned it into "specific becomes general."

I mean hey, if that's how you want your table to run, then house rule that you can disrupt spell casting by doing just about anything. But no need to pretend it's RAW, which it isn't.

[Rafaelfras]

This, I suppose.

If the game designers had wanted a spell to be cast in "parts" that lent it to easy disruption (which is what we are talking about here lets face it...allowing any Ready Action trigger to disrupt a spell makes it insanely easy to counter anything but a Subtle Spell), they could easily have added those rules. Where are they? Well, in the part about spells with a casting time greater than one Action, sort of. That casting is broken down into parts...so to speak. But only that extended duration of casting.

As a DM I would not for one second buy the argument...which has zero RAW support...that a viable trigger for a Ready Action's Reaction use is "starting to cast a spell," outside of saying, ok, so your Reaction goes off as soon as the spell is cast, which is pretty clearly the RAI...but the spell is still cast, not interrupted.

Just because something doesn't have any particular RAW contradiction/forbiddance doesn't make it "according to the rules."

Spells with a casting time of 1 Action, 1 Bonus Action, or 1 Reaction simply are not divided up by RAW into any meaningful "phases" such as "beginning to cast, casting, finished casting." However, there are specific things that are able to interrupt. This tells me the RAI is that only these specific things can interrupt the casting. Everything else waits until the spell is cast.

This, there isnt any situation in the book that calls for a concentration check to cast a 1 action, BA or Reaction spells. Stormy weather, high speed horses or charriots, boats on river or sea, etc. Nothing of those old situations is able to disrupt a caster on 1 action spells

[Rukelnikov]

The problem is, this is an extrapolation to general from a specific exception, which is the exact opposite of how 5e is supposed to work. (PHB Introduction, specific beats general) You've turned it into "specific becomes general."

I mean hey, if that's how you want your table to run, then house rule that you can disrupt spell casting by doing just about anything. But no need to pretend it's RAW, which it isn't.

It is. Ready requires you to specify a "perceivable circumstance" as trigger, the only possible argument against "begins casting a spell" as a trigger is that not being a perceivable circumstance. We know for a fact it is, since Counterspell is a thing, and reinforced by the fact that Subtle Spell, makes the casting of a spell not perceivable anymore and thus not a valid target for counterspell.

If you don't wanna allow it at your table, its another matter, but the rules allow for "begins casting a spell" to be a valid trigger.

[JoeJ]

If you don't wanna allow it at your table, its another matter, but the rules allow for "begins casting a spell" to be a valid trigger.

But for the purpose of the Ready action, they don't make any distinction between beginning to cast a spell and casting a spell

[Rukelnikov]

But for the purpose of the Ready action, they don't make any distinction between beginning to cast a spell and casting a spell

Is such a thing written in the ready action block? Where do you get that from?

[ProsecutorGodot]

If you can recognize the signs well enough to cast counterspell, you can recognize them well enough for it to be the trigger of a readied action.

Again, and for the final time, Counterspell is an exception and not the general rule. In fact, with how Counterspell is worded there's no indication that you've even pre-empted their casting in any way, simply that whatever interruption you've done has caused the end result to be a failure.

Whether or not you've pre-empted it or reacted to the absolutely last possible moment before the spell takes a real effect doesn't break any rules or the in world consistency of the spellcasting action or reaction rules.

However, for Ready Action to function in this way you have to create a circumstance where a trigger can occur and finish before it's end result happens. It's not internally consistent and it opposes the general rules for using a Readied Action.

We know for absolute certain as well that you're not intended to be able to be able to identify a spell being cast on the fly as evidenced by the Identifying a Spell rules in Xanathar's Guide. Yes, Xanathar's isn't strictly part of the Core Rules and doesn't have to be used at your table if you choose not to but what it does say is that the rules here are meant to clarify gaps in the PHB and DMG. This is a clear gap in the Core Rules.


This Intelligence (Arcana) check represents the fact that identifying a spell requires a quick mind and familiarity with the theory and practice of casting. This is true even for a character whose spellcasting ability is Wisdom or Charisma. Being able to cast spells doesn’t by itself make you adept at deducing exactly what others are doing when they cast their spells.
This makes sense to me, so I choose to use this as my basis for understanding a spell in the process of being cast.

Note that Counterspell specifically needs a spell to be cast for you to react with it, so it lets you cheat a little bit. That's just how the spell works.

[Contrast]

Because one focuses his training on speed, while the other focuses more on accuracy.

The rogue is actually a worse shot as well though (no fighting style).


He can. It's called critical hit. Also, he could have any other source of advantage than being hidden, or be a swashbuckler.

He can crit for 2d6+5 damage! Or if the guy steps 5ft to his left so he's now within 5ft of an ally he crits for 22d6+5 damage!


They don't. Turns and rounds only exist for the player's convenience, in fiction, the actions are simultaneous.

They're clearly not simultaneous though. Imagine a race where a trap door opens 30ft from the finish line when someone crosses it. Two people evenly matched in speed race for the finish line. Both should be fine right, they'll arrive at the finish line at the same time! But no, somehow one of them manages to be 30ft behind the other when he crosses the line and falls to his death.

Yes you shouldn't be using initiative for races but its common for similar things to arise in game with AoE effects or whatever.

But you're quite right, we pretend its simultaneous and paper over/ignore the inconsistencies that result from breaking the game down into rules which was the point I was making.


Exactly, the rules say "you decide what perceivable circumstance will trigger your reaction.". If I can perceive the casting of a spell well enough to counter it, then it is a perceivable circumstance, and thus a valid trigger for Ready Action.

Nope, rules don't say that. You don't need to specify an Action as the trigger, you can define any perceivable circumstance as the trigger, and your ready action comes after the trigger has finished.

Apologies when I said triggering action, I meant event or activity rather than Action.

This is obviously the point of contention so I think it's sufficient to just say we disagree on this point. If a player in a game I was DMing said they readied an action to attack someone if they cast a spell I'd tell them they'd get the spell off before the reaction triggered (like Mage Slayer), no amount of careful wording on their part of the trigger would allow it to resolve beforehand. In my mind the trigger finishing in this case is clearly the spell being cast and no degree of 'my trigger is the character beginning to make indications that they may be considering casting some sort of magic but to be clear not being in the middle of casting magic nosiree and definitely not the end of casting magic'. To me this smacks of someone saying 'I aim my attack so it doesn't hit the armour' and expecting the targets AC to be reduced.

This has already been discussed without any real progress so I guess my only real comment here is this is something to check with your DM about before attempting.

Out of interest would you allow a trigger of 'in the middle of casting a spell, after the point at which counterspell would have needed to have been cast but before completion of the spell' if there was another spellcaster in the fight who the PC thought might step in beforehand and didn't want to reveal themselves? You are obviously capable of perceiving someone casting Counterspell after all (after all it can be counterspelled... wait we can go deeper and nest another restriction of checking to see if their counterspell got counterspelled as well! :smallbiggrin:).

[Rukelnikov]

Again, and for the final time, Counterspell is an exception and not the general rule. In fact, with how Counterspell is worded there's no indication that you've even pre-empted their casting in any way, simply that whatever interruption you've done has caused the end result to be a failure.

Whether or not you've pre-empted it or reacted to the absolutely last possible moment before the spell takes a real effect doesn't break any rules or the in world consistency of the spellcasting action or reaction rules.

If someone casts a spell, and you decide not to counterspell, you have already realised the casting of such a spell was underway, and did nothing about it, your character has already perceived the casting of a spell was underway before it finished, there's no need for you to use Counterspell. So at the very least, anyone who knows or has counterspell prepared is able to perceive the casting of a spell being underway.


However, for Ready Action to function in this way you have to create a circumstance where a trigger can occur and finish before it's end result happens. It's not internally consistent and it opposes the general rules for using a Readied Action.

How does it oppose it? The ready action thing is fairly open, it requires you to define a circumstance and an action you will take in response to a trigger. Can I see someone swinging a sword in battle? Yes? Then it is a valid trigger.

What is not a valid trigger is saying "when X takes the Attack action", since the Attack action doesn't exist in-world and is not something a character can perceive. You could say when X attacks, which is a different thing.


We know for absolute certain as well that you're not intended to be able to be able to identify a spell being cast on the fly as evidenced by the Identifying a Spell rules in Xanathar's Guide. Yes, Xanathar's isn't strictly part of the Core Rules and doesn't have to be used at your table if you choose not to but what it does say is that the rules here are meant to clarify gaps in the PHB and DMG. This is a clear gap in the Core Rules.


This makes sense to me, so I choose to use this as my basis for understanding a spell in the process of being cast.

Note that Counterspell specifically needs a spell to be cast for you to react with it, so it lets you cheat a little bit. That's just how the spell works.

You need not identify the spell being cast, but again, the fact you can make a skill check to determine which spell IS BEING CAST, is further proof, that things can be done AFTER the casting begins and BEFORE it is completed.

[JoeJ]

Is such a thing written in the ready action block? Where do you get that from?

From the fact that it's not written in the description of the Ready action, and from the rule that readied actions always go after the trigger.

[Rukelnikov]

Out of interest would you allow a trigger of 'in the middle of casting a spell, after the point at which counterspell would have needed to have been cast but before completion of the spell' if there was another spellcaster in the fight who the PC thought might step in beforehand and didn't want to reveal themselves? You are obviously capable of perceiving someone casting Counterspell after all (after all it can be counterspelled... wait we can go deeper and nest another restriction of checking to see if their counterspell got counterspelled as well! :smallbiggrin:).

What makes you think there is a moment when counterspell is not valid anymore and the spell hasn't finished being cast?

There Isn't

[Rukelnikov]

From the fact that it's not written in the description of the Ready action, and from the rule that readied actions always go after the trigger.

After the trigger, we are all in the same page there, what we are discussing is what is a valid trigger.

There are at least 3 examples of things that can be done after a spell has begun being cast and before it ends. One of which can be done by any character (an Arcana check to determine the spell being cast). Thus "begins casting a spell" is a valid trigger.

[JoeJ]

After the trigger, we are all in the same page there, what we are discussing is what is a valid trigger.

There are at least 3 examples of things that can be done after a spell has begun being cast and before it ends. One of which can be done by any character (an Arcana check to determine the spell being cast). Thus "begins casting a spell" is a valid trigger.

What marks the point at which beginning to cast a spell is finished?

AFB at the moment, but I don't recall there being anything in the rules that distinguishes between beginning to cast a spell and casting a spell, unless the casting time is longer than 1 action.

[PhoenixPhyre]

After the trigger, we are all in the same page there, what we are discussing is what is a valid trigger.

There are at least 3 examples of things that can be done after a spell has begun being cast and before it ends. One of which can be done by any character (an Arcana check to determine the spell being cast). Thus "begins casting a spell" is a valid trigger.

Not necessarily. You're reasoning from specific to general, which is invalid in an exception-based game. The existence of exceptions does not imply a general rule.

Reactions are each their own separate exception to the basic flow of combat (which only allows movement and one Action, with a potential object interaction as part of the Action). Each reaction has its own rules, and none of them interact with or implicate any other unless they explicitly say they do. As a note, so are spells and bonus actions.

[Rukelnikov]

What marks the point at which beginning to cast a spell is finished?

AFB at the moment, but I don't recall there being anything in the rules that distinguishes between beginning to cast a spell and casting a spell, unless the casting time is longer than 1 action.

You can make an arcana check as a reaction to identify a spell being cast. Anyone can do this.

[jh12]

If instead of an attack you readied Silence, you could cast it on the area around the enemy caster and thus prevent the spell from being cast (if it includes a verbal component)

If the enemy caster still had movement left, why couldn't the enemy caster move 21 feet and finish casting once out of the sphere of silence? The enemy caster hasn't used his Action yet.

[Rukelnikov]

Not necessarily. You're reasoning from specific to general, which is invalid in an exception-based game. The existence of exceptions does not imply a general rule.

Reactions are each their own separate exception to the basic flow of combat (which only allows movement and one Action, with a potential object interaction as part of the Action). Each reaction has its own rules, and none of them interact with or implicate any other unless they explicitly say they do. As a note, so are spells and bonus actions.

Care to explain the rules of the Ready action's reaction, then?

[Rukelnikov]

If the enemy caster still had movement left, why couldn't the enemy caster move 21 feet and finish casting once out of the sphere of silence? The enemy caster hasn't used his Action yet.

I never said they couldn't

[ProsecutorGodot]

If someone casts a spell, and you decide not to counterspell, you have already realised the casting of such a spell was underway, and did nothing about it, your character has already perceived the casting of a spell was underway before it finished, there's no need for you to use Counterspell. So at the very least, anyone who knows or has counterspell prepared is able to perceive the casting of a spell being underway.
The specific mechanical trigger out of game does not give your character the knowledge that a spell is being cast in world, like I said, Counterspell cheats a little bit because otherwise it would be entirely nonfunctional for its intended use.

Kind of like how Ready Action isn't very functional as a Counterspell.

You can make an arcana check as a reaction to identify a spell being cast. Anyone can do this.
Yes, and then you can't make the same reaction also attack them in an attempt to stop/hinder their casting.

You either get to identify that a spell is being cast or attack not knowing for sure if a spell is being cast.

[Contrast]

What makes you think there is a moment when counterspell is not valid anymore and the spell hasn't finished being cast?

There Isn't

The fact that I can perceive someone casting Counterspell makes it an acceptable trigger though according to you.

Are you saying you wouldn't allow the trigger 'The enemy wizard starting to cast a spell and not being counterspelled'?

I'm honestly asking how you would resolve a player doing this as the as the answer clearly isn't time stretching into infinity as we enter a recursive loop of checking if anyone wants to counterspell, checking if the trigger has triggered, checking it anyone wants to counterspell...etc etc.

[JoeJ]

You can make an arcana check as a reaction to identify a spell being cast. Anyone can do this.

Okay. Does the text actually say this happens after the caster finishes starting to cast but before the spell is cast?

[Rukelnikov]

Yes, and then you can't make the same reaction also attack them in an attempt to stop/hinder their casting.

You either get to identify that a spell is being cast or attack not knowing for sure if a spell is being cast.

I don't wanna do the check. But my ability to do so proves, in-game, my character is aware that a spell is being cast, and can react to that situation.

[PhoenixPhyre]

Care to explain the rules of the Ready action's reaction, then?

Actions are atomic--there's no space in the flow between "player declares action" and "DM and player resolve action" unless something specifically overrides that (as an explicit exception). The Ready action does not make an explicit exception. Thus, whatever the trigger, the reaction takes place after the action that triggered it. By it's own rules.

"After the trigger" and "after the action or movement that caused the trigger to fire" are synonyms here. Because by the default rule, there is nothing in combat (the only time you can take the Ready action) that isn't an action or movement.

By the time you know he's casting a spell, it's too late to do anything about it except for counterspell. Why? Because counterspell says you can do so (as an exception to the general flow). Even taking a reaction to identify the spell lets you know what it is after the spell happens (by any reasonable reading). Which makes it not very useful for fireball, but still very useful for those less obvious spells (like dominate person).

[ProsecutorGodot]

I don't wanna do the check. But my ability to do so proves, in-game, my character is aware that a spell is being cast, and can react to that situation.

That's such a ridiculous argument that I truly do not know how to respond to it.

How does your ability to make an active check guarantee that you have already succeeded in making an active check that you are choosing not to take?

That's akin to saying "My + To Hit is high enough that I'm able to hit, anyone can roll a natural 20 as well so I'm just going to take the 20 and roll damage"

[jh12]

I never said they couldn't

Sure you did. You said you could use Silence to prevent the spell from being cast. Casting the same spell on the same turn from 21 feet away is not preventing a spell from being cast. And it doesn't seem any better than casting silence on your turn instead of waiting for theirs (much like waiting to shoot them).

[Rukelnikov]

That's such a ridiculous argument that I truly do not know how to respond to it.

How does your ability to make an active check guarantee that you have already succeeded in making an active check that you are choosing not to take?

That's akin to saying "My + To Hit is high enough that I'm able to hit, anyone can roll a natural 20 as well so I'm just going to take the 20 and roll damage"

I haven't succeeded cause I didn't even try. I don't care which spell is being cast. I only care about knowing that a spell, whichever it is, is being cast.

[Max_Killjoy]

Actions are atomic--there's no space in the flow between "player declares action" and "DM and player resolve action" unless something specifically overrides that (as an explicit exception). The Ready action does not make an explicit exception. Thus, whatever the trigger, the reaction takes place after the action that triggered it. By it's own rules.

"After the trigger" and "after the action or movement that caused the trigger to fire" are synonyms here. Because by the default rule, there is nothing in combat (the only time you can take the Ready action) that isn't an action or movement.

By the time you know he's casting a spell, it's too late to do anything about it except for counterspell. Why? Because counterspell says you can do so (as an exception to the general flow). Even taking a reaction to identify the spell lets you know what it is after the spell happens (by any reasonable reading). Which makes it not very useful for fireball, but still very useful for those less obvious spells (like dominate person).

If you have time to cast Counterspell, why don't have you have time to do anything else... other than "because the rules said so"?

[Rukelnikov]

Actions are atomic--there's no space in the flow between "player declares action" and "DM and player resolve action" unless something specifically overrides that (as an explicit exception). The Ready action does not make an explicit exception. Thus, whatever the trigger, the reaction takes place after the action that triggered it. By it's own rules.

"After the trigger" and "after the action or movement that caused the trigger to fire" are synonyms here. Because by the default rule, there is nothing in combat (the only time you can take the Ready action) that isn't an action or movement.

The rules don't say the trigger has to be movement or an action. I could choose for my trigger to be "when the tower's clock shows 12 o clock"

The rules only restriction on the trigger is that it has to be a "perceivable circumstance" and so far everyone has been deflecting the argument of how can "begins casting a spell" not be a perceivable circumstance if my character can react to it.


By the time you know he's casting a spell, it's too late to do anything about it except for counterspell. Why? Because counterspell says you can do so (as an exception to the general flow). Even taking a reaction to identify the spell lets you know what it is after the spell happens (by any reasonable reading). Which makes it not very useful for fireball, but still very useful for those less obvious spells (like dominate person).

Identifying says a spell BEING cast, if it had already finished being cast, it would have to say a spell that has been cast. Further proof is that RAI (tweeter) one player can identify the spell being cast and convey the information so that another player can counterspell it.

[Rukelnikov]

If you have time to cast Counterspell, why don't have you have time to do anything else... other than "because the rules said so"?

Where exactly?

[Max_Killjoy]

Where exactly?

Note the quotation marks -- I make no assertion that the rules say or do not say this, I'm asking a separate question about something a bit more fundamental about 5e.

[Rukelnikov]

Note the quotation marks -- I make no assertion that the rules say or do not say this, I'm asking a separate question about something a bit more fundamental about 5e.

Sry my bad, I'm having to follow like 5 different conversations already.

[PhoenixPhyre]

If you have time to cast Counterspell, why don't have you have time to do anything else... other than "because the rules said so"?

You don't. By default there is no time to do anything. Except counterspell, like shield, lets you act where you otherwise couldn't.

And at some level, "because the rules say you can't" is not only a true answer, but the only true answer. When you're working at the level of the game abstraction, the workings are defined by the rules. They should correlate with the fiction, but they'll never do so perfectly. And so when asked "why not" about a game thing, "because the rules say you can't" is a perfectly good answer.

[Max_Killjoy]

You don't. By default there is no time to do anything. Except counterspell, like shield, lets you act where you otherwise couldn't.

And at some level, "because the rules say you can't" is not only a true answer, but the only true answer. When you're working at the level of the game abstraction, the workings are defined by the rules. They should correlate with the fiction, but they'll never do so perfectly. And so when asked "why not" about a game thing, "because the rules say you can't" is a perfectly good answer.

If by default you don't have time to do anything, how do you have time to do either of those two things?

Or perhaps a better question, how much time is actually passing, that most things are impossible but those two are not?

[ProsecutorGodot]

If you have time to cast Counterspell, why don't have you have time to do anything else... other than "because the rules said so"?

It's kind of hard to answer this question since it really is as simple as "the rules say so". With the default way that actions in combat are structured at least. Reactions have their own timings, Readied Action happens after the trigger and "beginning to cast a spell" isn't a trigger that you can respond to afterward while still having it happen "before the spell is cast". The idea that a reaction can be used in response to a "the beginning of a spell being cast" only exists in the reactions that specifically allow it.

This is something that I think the Greyhawk Initiative UA did better, where instead of having a sequential round based system is was more dynamic and allowed actions to be interrupted with pre-emptive planning rather than reactionary queues.

And of course, I feel the need to repeat, I'm perfectly okay with making exceptions if it seems appropriate. There may be a time where the situation makes sense for an arrow to successfully interrupt a spellcaster but that isn't always going to be then case. Something being able to happen doesn't guarantee that it always will happen.


If by default you don't have time to do anything, how do you have time to do either of those two things?

Or perhaps a better question, how much time is actually passing, that most things are impossible but those two are not?

Seconds, or fractions of them as reactions are concerned. The round encompasses a time of 6 seconds total so if we're trying to adjudicate the actions of a number of creatures (I'd expect at least 6 in any given encounter) then we have to suspend our disbelief a bit on what is possible in that timeframe.

That's why features specifically alter what you're able to do in that window, such as Extra Attack making you able to strike more in a 6 second window or Quickened Spell allowing Sorcerer's to do an extended amount of spellcasting in that small window. The rules facilitate the fantasy.

[Foxydono]

This is a fun argument! I've read about half the comments and there is a fair argument to be made for both cases. My guess is that the developers intentionally left the rules very vague because they didn't want too many rules. Unfortunately, sometimes this has an adverse effect like in this case.

If I were te DM, I'd just rule what makes sense to me. And to be honest, interrupting a spell should be allowed under certain circumstances with the ready action. An action takes six seconds and so does casting most spells. I don't see a reason not to allow it at my table if they word there rdy action correctly and their plan seems plausible.

Saying you can't interrupt a spell because it doesn't state so by raw seems silly to me. Also, it's much more fun to allow it and it can be used by the DM as well of course :)

[ThePolarBear]

the only possible argument against "begins casting a spell" as a trigger is that not being a perceivable circumstance. We know for a fact it is, since Counterspell is a thing

No. We know that "being in the process of casting a spell" is perceivable. That is the trigger for Counterspell. "Beginning" is not part of it.


If someone casts a spell, and you decide not to counterspell, you have already realised the casting of such a spell was underway,

Yes. I would add a "clearly".


your character has already perceived the casting of a spell was underway before it finished, there's no need for you to use Counterspell. So at the very least, anyone who knows or has counterspell prepared is able to perceive the casting of a spell being underway.

Which is still a far fetch from being able to identify when something begins the moment it does.

If it is the "casting of the spell" that is the perceivable part, you need to "prove" that the "begins" is also perceivable. (spoilers, its' not. "Begins" is an artificial simplification based on a mixture of actual perceiveable phoenomena and judgment on the meaning of those occurrences.)

For any intents and purposes, if you connect "casting a spell" with "begins casting a spell" in this way, you would need to wait until "finishes casting a spell", not "finishes beginning casting a spell".

The problem is that you can mix the unmentioned perceiveable occurrences that indicate that a spell is being cast, whatever those are, with those unmentioned perceiveable occurrences that might indicate that something is "about" to happen. The game asks you to make a decision on a specific "something" to avoid problems.

Making a bit of an extreme example here: if we were to ready an action "when the fire starts" in a situation when someone is using sticks to light it, we would not be able to really determine when it does start without a specific event: for me, it might mean when there's the first flame. For you, when there's the first smoke rising. For a third person, a third thing.

We can have troubles with "mundane" (as in, real-life possible) things; It's just that hard and imprecise.
If we apply it to something utterly fantastical and unexisting as magic...

[JoeJ]

Or perhaps a better question, how much time is actually passing, that most things are impossible but those two are not?

The only possible answer to that is however much you want to describe it as. The rules don't explain in detail how the different spells work, leaving it completely open whether Counterspell actually is faster than the target spell, or goes off at the same time, or goes slightly afterward and cancels the spell after it leaves the caster, or even occurs a second or two after the spell and works backward in time. RAW, it causes the spell to have no effect, but how it does that is not explained.

[Rukelnikov]

You don't. By default there is no time to do anything. Except counterspell, like shield, lets you act where you otherwise couldn't.

And at some level, "because the rules say you can't" is not only a true answer, but the only true answer. When you're working at the level of the game abstraction, the workings are defined by the rules. They should correlate with the fiction, but they'll never do so perfectly. And so when asked "why not" about a game thing, "because the rules say you can't" is a perfectly good answer.

But the rules say you can. Example:

ME: "I close the door if someone begins casting"

DM: "Warlock casts a spell, anyone gonna counterspell?"

ALLY: "I can't counter but wanna Identify it"

Rolls n fails

ME: "Can I attempt to Identify it?"

DM: "Yes"

ME: "Does that mean I'm aware a spell is being cast?"

DM: "... No..."

ME: "Then what would I be identifying?"

DM: "Which spell the lock is casting"

ME: "So I know it's casting a spell?"

DM: "... No..."

And so on and so forth

[JoeJ]

ME: "Does that mean I'm aware a spell is being cast?"

DM: "... No..."


Where did this come from? Who says you're not aware a spell is being cast?

[Rafaelfras]

It doent matter.There is no rule saying that you need to take a concentration saving throw when you take damage while casting a spell that require 1 action, a BA or a reactiong, otherwise you would have to take one while being afected with spells and abilities that do ongoing damage like melfs acid arrow, firewall death fog, poisons, etc. There is o such rule, you can cast inside a firewall as well as normal.
Whatever or not yopu take damage before you end your spell it doesnt matter (unless it leaves you with 0 hp, but this is a very specific rulling) the spell will get off anyway, because there is no rule saying otherwise

[ProsecutorGodot]

Where did this come from? Who says you're not aware a spell is being cast?

I brought up the fact that using your trigger as "beginning to cast a spell" isn't a reasonable way to prevent the spell from being cast, by virtue of not being fully sure on whether such motions/materials being waved around are directly related to a spell being cast.

This was specific to the Readied Action specifically, as Identifying a Spell and Counterspell are timed in a way that allows you to cheat a bit in reacting (with those specific reactions) to a spell being cast, which you would know since the only way to react in that way is for a spell to be cast.

To simplify, Counterspell and Identifying a Spell can only be used in response to a spell being cast, so obviously your character is aware that it's happening. This also logically follows that if you don't intervene in some way, the spell completes. For a Readied Action of "when they begin to cast a spell" the creature could do something that you percieve to be a spellcasting related movement, but might not be since you were so hasty in your reaction.

Obviously, this is my own interpretation, but at this point I'm confident the one universal thing we can agree on is that the rules here are ambiguous in a way that could allow either interpretation without being explicitly against the other.

[Sigreid]

Has to be said, kill the fool before it's his turn.

[Naanomi]

It doent matter.There is no rule saying that you need to take a concentration saving throw when you take damage while casting a spell that require 1 action
True, although you essentially end up with the same ‘reaction speed’ question when you add in stunning fist or whatever actually *would* shut down the spell

[CorporateSlave]

You need not identify the spell being cast, but again, the fact you can make a skill check to determine which spell IS BEING CAST, is further proof, that things can be done AFTER the casting begins and BEFORE it is completed.

Your insistence about a trigger doesn't really matter, because the issue is whether your Reaction interrupts. You are taking specific exceptions (Counterspell, etc) and expanding them to general guidelines. It's a fine "attorney's argument," except that 5e is quite explicit on the matter than specific beats general...which means that specific exceptions should not be expanded to general guidelines.

Sure, you can word the trigger however you want. But only specific exceptions like Counterspell can interrupt casting.

If anything, your evidence that certain things like Counterspell allow you to interrupt is evidence that refutes your position, because the fact that they specifically do allow an interruption implies that generally no interruption is allowed by normal means, when no general method for interrupting a spell with casting time of 1 Action (or less) is described in the general rules, but a method for interrupting a spell with a casting time greater than 1 Action is described.

[Missing]

In relation to readied attacks that could potentially stop the spell being cast, through doing enough damage or a monk's stunning fist ability, I personally feel that they HAVE to be too slow to prevent the spell 'going off'.

My reasoning is thus:
1. A spell and an attack take 1 Action to complete. Lets give this a value of T
2. Your readied action is to attack when the target starts casting (for now we assume that this is a valid trigger)
3. The target 'begins casting a spell'. This takes T
4. A TINY amount of time passes between the spell beginning and you realizing the spell has been started. Lets give this time a value of y
5. Your readied action begins also taking T however by this time the Spell has T-y time left.
6. The spell goes off and y later your attack lands, possibly killing or stunning the target BUT the spell wasn't stopped.

An issue I have with the 'when they reach for the spell component pouch' is that until they grab it how do you know that that's what they were doing, especially if they have multiple items on their belt. Secondly there is no defined order of operations to cast a spell, like it could be focus on the magic, wave hands, say words, grab pouch or any other order.

Finally as others have pointed out if the target hasn't moved yet they can just walk outside the area of the Silence spell.
Hold Person might work depending on the trigger specified, I would probably allow it as its not really the best use of a Hold Person, since its the targets turn they get to save vs. the cast and again at the end of their turn.

[Max_Killjoy]

The only possible answer to that is however much you want to describe it as. The rules don't explain in detail how the different spells work, leaving it completely open whether Counterspell actually is faster than the target spell, or goes off at the same time, or goes slightly afterward and cancels the spell after it leaves the caster, or even occurs a second or two after the spell and works backward in time. RAW, it causes the spell to have no effect, but how it does that is not explained.

To me the entire thing is backwards -- not knowing the time involved, we can't answer the basic question of this thread.

[ProsecutorGodot]

To me the entire thing is backwards -- not knowing the time involved, we can't answer the basic question of this thread.

Well, we do have a chain of events, Readied Actions must happen after their trigger, Counterspell happens instantly (at an undefined point, since "casting a spell" isn't specifically defined in it's length for single action spells) and Opportunity Attacks happen before.

We also have other information that we can use to estimate the time to cast spells though:
-Your turn happens simultaneously to the other combatants turns in the fantasy
-Rounds, not turns, are 6 seconds long
-Most spells take seconds to cast, some longer
-It's only possible to cast 2 spells per turn, one of which must be a bonus action.
-Reaction spells are even faster than bonus action spells taking only fractions of a second to cast, however, they cannot be cast without an applicable trigger.
-It's only possible to cast up to 3 spells per round.

With all this information available, I don't think it's totally out of the question to build a timeframe. Spells with a casting time of 1 action are between 2-6 seconds in casting time, bonus action spells likely between 1-3 and Reaction spells taking at most 1.

Is this exactly what they are? Probably not, but it's not likely to be far off.

EDIT: This isn't necessarily relevant though. This timescale is only important in combat, where we need to worry about this time crunch being important. If you think that "casting a spell" leaves a window at your table where "casting a spell" can end and you can react with an attack after that but before "a spell has been cast" then more power to you in that regard, it's not super clear either way.

I am of the opinion that "after" is the key part in Ready Action where you are intended to react to the desired trigger and not pre-empt it and I believe that a lack of distinction between "casting" and "cast" outside of very specific features means that there isn't meant to be such a distinction, so such a trigger in Ready Action would allow the spell to complete before you react.

[Nhorianscum]

Has to be said, kill the fool before it's his turn.

This is effectively the "arrow in the neck" trope you're looking for.

[CorporateSlave]

To me, the entire thing, is! Backwards -- not knowing. The time involved...we can't! Answer the basic question of this thread!!!

What the devil are you talking about?!?

:smallbiggrin:

Sorry mate, couldn't resist. At least I got all the words right this time!

Seriously though, the time involved isn't relevant, because the real question is, do the rules state a general method for interrupting a spell being cast? Yes...but...only a spell with a casting time of greater than 1 Action.

There are specific exceptions of course, such as the oft referenced Counterspell. But this is a specific exception, and a core philosophy of 5e is that specific exceptions can break general rules. The general rules only state you can interrupt the casting of a spell with a casting time of greater than 1 Action. Specific exceptions exist that allow specific Reactions (like Counterspell) to interrupt casting. But that doesn't mean that any Reaction can interrupt, just the specific exceptions.

[Naanomi]

To be fair, it is conceivable that someone could cast four spells in one turn, albeit a round where you’d have to contrive a reaction during your own round (it can happen, for example shielding against an attack of opportunity; or counterspelling a Counterspell) and action-surging

[Aquillion]

What the devil are you talking about?!?We're in Exalted territory now (http://forum.theonyxpath.com/forum/main-category/exalted/732904-i-m-just-going-to-leave-these-vandalized-chapter-comics-here).

[ProsecutorGodot]

To be fair, it is conceivable that someone could cast four spells in one turn, albeit a round where you’d have to contrive a reaction during your own round (it can happen, for example shielding against an attack of opportunity; or counterspelling a Counterspell) and action-surging

Unless I'm missing something (I'm tired, it's entirely possible) 3 is generally the most you're going to get in a round, unless you're a Fighter/Sorcerer who quickens a spell.

Action - Cantrip
Action Surge - Cantrip
Bonus Action - Anything
Reaction (outside of turn) - Anything

It's pretty specific and not going to happen often.

For the reaction to be able to happen on your turn you would either need a cantrip that could be used as a Reaction, allowing your BA to be any spell or a bonus action Cantrip, allowing your reaction to be any spell. Bonus Action Cantrip is doable with MI Druid or Warlock for Magic Stone (Druid also gets Shillelagh) or multiclassing Grave Cleric. I don't think a Reaction cantrip exists.

[Naanomi]

Unless I'm missing something (I'm tired, it's entirely possible) 3 is generally the most you're going to get in a round, unless you're a Fighter/Sorcerer who quickens a spell.

Action - Cantrip
Action Surge - Cantrip
Bonus Action - Anything
Reaction (outside of turn) - Anything

It's pretty specific and not going to happen often.

For the reaction to be able to happen on your turn you would either need a cantrip that could be used as a Reaction, allowing your BA to be any spell or a bonus action Cantrip, allowing your reaction to be any spell. Bonus Action Cantrip is doable with MI Druid or Warlock for Magic Stone (Druid also gets Shillelagh) or multiclassing Grave Cleric. I don't think a Reaction cantrip exists.
Edit: eh maybe

If I want to be *especially* pedantic, Wild Surges could keep giving me extra actions to throw out more and more spells until I ran out of slots

[Aquillion]

Unless I'm missing something (I'm tired, it's entirely possible) 3 is generally the most you're going to get in a round, unless you're a Fighter/Sorcerer who quickens a spell.

Action - Cantrip
Action Surge - Cantrip
Bonus Action - Anything
Reaction (outside of turn) - Anything

It's pretty specific and not going to happen often.

For the reaction to be able to happen on your turn you would either need a cantrip that could be used as a Reaction, allowing your BA to be any spell or a bonus action Cantrip, allowing your reaction to be any spell. Bonus Action Cantrip is doable with MI Druid or Warlock for Magic Stone (Druid also gets Shillelagh) or multiclassing Grave Cleric. I don't think a Reaction cantrip exists.
You can cast most cantrips as reactions using War Caster. Just make the Bonus Action spell a quickened Dissonant Whispers to provoke an attack of opportunity on your turn. Then you cast another cantrip on your action and with your Action Surge.

[ProsecutorGodot]

The rule concerning spells in a round only address bonus actions, it says nothing about reaction spells...

“Bonus Action
A spell cast with a bonus action is especially swift. You must use a bonus action on your turn to cast the spell, provided that you haven’t already taken a bonus action this turn. You can’t cast another spell during the same turn, except for a cantrip with a casting time of 1 action.”

I could easily cast a cantrip, quicken a normal spell, counterspell the counter to my spell, action surge another cantrip....

If I want to be *especially* pedantic, Wild Surges could keep giving me extra actions to throw out more and more spells until I ran out of slots

The bolded is the important part, if you plan to cast a spell as a bonus action you're not casting anything as a reaction or vice versa during that turn. Outside of your turn is A-OK though.

Round =/= Turn, I thought I was clear on the difference. Generally, you're only going to be casting a maximum of 3 spells per round. There are some specific ways to circumvent that.

Is it a silly limitation? Absolutely, but it's there.


You can cast most cantrips as reactions using War Caster. Just make the Bonus Action spell a quickened Dissonant Whispers to provoke an attack of opportunity on your turn. Then you cast another cantrip on your action and with your Action Surge.
Not what I'm arguing. All of this was simply meant to establish what is generally allowed, I'm well aware that there are specific ways to circumvent this.

The idea that specific features allow general rules limitations to be broken is one of the core tenants to 5E.

[Naanomi]

Ok so... level 20 Sorcerer

-Use Warcaster to throw a cantrip at someone during voluntary movement they get on my turn somehow (there are a few ways)
-Cast a spell out of each of my 22 Sorcerer Spell slots, rolling a 81-82 on each of my wild surges for another action and cast another spell
-use my bonus action to convert Sorcerer points into another spell slot
-cast it


24 spells cast in one round, never bonus action cast so never run into the Bonus Action rules

Could happen 1/22,000 times I think...

[ProsecutorGodot]

Ok so... level 20 Sorcerer

-Use Warcaster to throw a cantrip at someone during voluntary movement they get on my turn somehow (there are a few ways)
-Cast a spell out of each of my 22 Sorcerer Spell slots, rolling a 81-82 on each of my spell surges for another action and cast another spell
-use my bonus action to convert Sorcerer points into another spell slot
-cast it


24 spells cast in one round, never bonus action cast so never run into the Bonus Action rules

Could happen 1/22,000 times I think...

Wild Magic can only happen once per turn. You're unlikely to trigger it, it's also very unlikely that it gives you an extra action. You could argue that "Once per turn" isn't "Once on your turn" so it could also roll on your reaction (I would probably allow this if my player wanted it) but then, having another action doesn't really help you. You could instead roll on one of the effects that casts a spell from your surge.

So, in the incredibly unlikely scenario where you are a Fighter/Sorcerer who quickens a leveled spell, managed to gain an extra action through the wild magic surge and uses their action surge to cast an additional cantrip. 3 cantrips, 1 Quickened Spell and a Reaction spell that also surges and casts an additional spell like Fireball or Invisibility, you are casting 6 spells in a round.

If this ever happens to you in a real game, I'd play some lottery or go visit a casino.

[Naanomi]

Where is the restriction on Wild Surge/round listed? My PHB says “Immediately after you cast a sorcerer spell of 1st level or higher, the DM can have you roll a d20. If you roll a
1, roll on the Wild Magic Surge table to create a random magical effect.“ without any other caveats

Edit: the odds of this occuring are (1/20 chance of wild surge X 2/100 odds of extra action)/23 spells... so 1/23,000 rounds when you have full spell slots and at least 2 sorcery points... exceedingly altars, but not ‘win the jackpot on the lottery’ rare by any means

Oh, and I guess I can tack one more cantrip on the end of the routine so... a nice 25 spells!

[ProsecutorGodot]

Where is the restriction on Wild Surge/round listed? My PHB says “Immediately after you cast a sorcerer spell of 1st level or higher, the DM can have you roll a d20. If you roll a
1, roll on the Wild Magic Surge table to create a random magical effect.“ without any other caveats

You must have a pretty old print of the PHB, this was made into an Errata in 2017 (https://media.wizards.com/2017/dnd/downloads/PH-Errata.pdf) (perhaps sooner, 2017 is the earliest I could find)

The current full text reads as follows:

Wild Magic Surge
Starting when you choose this origin at 1st level, your spellcasting can unleash surges of untamed magic. Once per turn, the DM can have you roll a d20 immediately after you cast a sorcerer spell of 1st level or higher. If you roll a 1, roll on the Wild Magic Surge table to create a magical effect. If that effect is a spell, it is too wild to be affected by your Metamagic, and if it normally requires concentration, it doesn’t require concentration in this case; the spell lasts for its full duration.

[Naanomi]

You must have a pretty old print of the PHB, this was made into an Errata in 2017 (https://media.wizards.com/2017/dnd/downloads/PH-Errata.pdf) (perhaps sooner, 2017 is the earliest I could find):
Ah, yeah my copy is pretty old... but given that info:

Technically (unless there is other text not represented in the errata in newer printings), the restriction is only on having me roll when I cast a spell once... not that I can only Wild Surge once... so...

1) I can get one more wild surge if I rolled a ‘01-02’ on the Wild Surge chart in a previous round; which I can use to roll an ‘81-82’ for an action, which I can use to cast a cantrip

2) I can recharge my Tides of Chaos an unlimited number of times a round if I can keep spending it fast enough; let us say by retooling Attack rolls on all of my spells... which... hold on...puts me back in a loop to cast all of my spell slots, as long as they require attack rolls!

So...
22 base spell slots
1 more spell slot created by Sorcerer Points (assuming I’m not allowed to stockpile them ahead of my normal max ahead of time coffee-lok style)
1 Cantrip from Warcaster Reaction
1 More cantrip on the Action I gain from my last spell slot
1 more cantrip on the ‘01-02’ result from the round before, which gives me another action (use Sorcerer points to refill the spell slot)

26 spells/round!

EDIT:
High Elf Cavalier 18+ with Warcaster; an infinite supply of 1HP birds fly by her from the Elemental Plane of Pedantic Rule Discussions... she gets infinite spells that round as she blasts them out of the air... wait, what were we talking about again?

Oh yeah, seems like at least some degree of GM adjudication is at play as to what exactly can trigger a reaction, so actual results will vary

[ProsecutorGodot]

Ah, yeah my copy is pretty old... but given that info:

Technically (unless there is other text not represented in the errata in newer printings), the restriction is only on having me roll when I cast a spell once... not that I can only Wild Surge once... so...

1) I can get one more wild surge if I rolled a ‘01-02’ on the Wild Surge chart in a previous round; which I can use to roll an ‘81-82’ for an action, which I can use to cast a cantrip

2) I can recharge my Tides of Chaos an unlimited number of times a round if I can keep spending it fast enough; let us say by retooling Attack rolls on all of my spells... which... hold on...puts me back in a loop to cast all of my spell slots, as long as they require attack rolls!
I don't see how you can read "Once per turn, the DM can have you roll a d20 immediately after you cast a sorcerer spell of 1st level or higher." as allowing you to do it... More than once per turn. I'm really confused about how you're reaching the conclusion that you are.

If you mean the second paragraph of Tides of Chaos, I'd be so done at the table if the DM decided to just go with that because they decide if Tides of Chaos triggers a Wild Magic Surge, it doesn't happen automatically. It also has to happen after the spell is cast so how are you going to sequentially use Tides of Chaos over and over?

Hypothetically, if you were allowed to roll 20+ times on the table, I'm not too hot on statistics but I feel like the percentage chance of it happening is even lower than you're claiming since it doesn't just take into account the 2/100 chance of doing it once but the 2/100 chance of doing it twice in a row, then three times in a row, then four times in a row and so on. It's not an additive statistic, it's multiplicative since you must meet the 2/100 chance for each one altogether, not independently.

The first Wild Magic surge is a 1/1000 occurence (triggering a Wild Magic Surge and having it select rolling a Wild Magic Surge at the start of your turn for 10 turns), 1/1000 again for rolling an extra action on the subsequent turn. then, assuming that I've guessed correctly on how you believe that this functions, 2/100 for subsequent additional actions since apparently the Wild Magic Surge is now guaranteed.

.001*(.0220)=1.048576e-37
the 20 is how many times an additional action rolls, I'm stopping at 20 because this is already nigh impossible

For the singular desired result of having cast 20 additional spells through gaining 20 additional actions while also having rolled to trigger our wild magic surge at the start of our turns sequentually and without failing, our odds are 1/10485760000000000000000000000000000000

If I've got this wrong, please feel free to correct me. I haven't opened up a math book since high school and I swear I've completely forgotten probability mathematics.

my point being, regardless of who is correct with the mathematics, is just because this exception can occur doesn't mean it's likely to. This is entirely off topic at this point.



EDIT:
High Elf Cavalier 18+ with Warcaster; an infinite supply of 1HP birds fly by her from the Elemental Plane of Pedantic Rule Discussions... she gets infinite spells that round as she blasts them out of the air... wait, what were we talking about again?
War Caster replaces your opportunity attack with a spellcast.

When a hostile creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, rather than making an opportunity attack. The spell must have a casting time of 1 action and must target only that creature.

The Cavalier 18th only allows additional AoA

Starting at 18th level, you respond to danger with extraordinary vigilance. In combat, you get a special reaction that you can take once on every creature’s turn, except your turn. You can use this special reaction only to make an opportunity attack, and you can’t use it on the same turn that you take your normal reaction.
So this doesn't fly either.

[Naanomi]

The limitation on Wild Surges is part of the Wild Magic Surge ability... it doesn’t appear to inherently limit Wild Surges from occuring from other sources; including those from previous Wild Surges (rolling a 1-2 in a previous Wild Surge); nor from recharging your Tides of Chaos.

If you had a GM who supported Maximum Wildsurge (every Spell rolls; Tides of Chaos recharges at every opportunity) then you expend each Tides of Chaos by getting Advantage on an attack roll, the GM elects to recharge it, and sets up the next spell to Surge again until you just don’t have any spells of level 1 or higher to keep the chain going

And you are probably right on the math actually, but hey... it is an infinite multiverse; I’m sure it has happened to a Sorcerer somewhere

[Aquillion]

Not what I'm arguing. All of this was simply meant to establish what is generally allowed, I'm well aware that there are specific ways to circumvent this....why, though? I think I've lost the thread of what this is supposed to be establishing. I think everyone agrees that:

1. Under some fairly unusual circumstances, it's possible to cast 4 spells in a turn (maybe even more - I'm sure there's some bizarre interactions out there.) You could even cast more than one non-cantrip as long as they're not your bonus action.

2. Those circumstances are, outside of very specific builds, fairly rare.

I think the idea was to argue over the time involved in one round and what can be accomplished in it? But I'm not sure why that matters precisely, and to the extent that it does matter the point that yes, it is possible to squeeze unusual amounts of stuff into a round sometimes seems pretty clear.

I mean... even Spell, Action Surge to cast another spell, cast a third spell with War Caster establishes that, and that situation isn't that implausible (many gish builds take both Action Surge and War Caster.) The third spell doesn't have to even be on your turn, not if we're arguing over "how much can you squeeze into one round" (for whatever reason.)

Heck, as long as we count spells at any point in the round, it's not that hard to picture a build that would hit four spells (including three cantrips) reasonably often, now that I think about it - the only odd part is that it's pretty unusual for someone to spend their action surge on a cantrip. Some sort of Warlock / Fighter build where you drop a Hex and then Eldritch Blast repeatedly could hit three spells pretty often and four spells whenever their reaction is triggered on their initial nova turn.

[CorporateSlave]

...why, though? I think I've lost the thread of what this is supposed to be establishing. I think everyone agrees that:

I think the idea was to argue over the time involved in one round and what can be accomplished in it?

Ah, the fate of forum threads! The original original idea was to figure out what are all the available ways to disrupt and negate a spell being cast, and here we have shifted to discussing the opposite; how to cast as many spells as possible!

Arguing over the time involved had to do with "real world common sense" attempts to justify breaking spell casting down further into steps which would present an opportunity to interrupt the casting by intervening in between steps (i.e. "beginning to cast" vs "finish casting").

Of course, the RAW does not make any such distinction for "short" casting time spells (1 Action or less casting time), so according to the RAW (and almost certainly RAI) there should be no way to interrupt such spells outside of certain exceptions due to spells or sub-class abilities. (Which led to the discussion of general vs specific)

5e was intended to simplify things, if you want overly cumbersome combat mechanics and easy ways for anyone to interrupt spell casting, isn't there a 3.5e out there that fits the bill?

It would be nice to have some SA input on this, if only for a better idea of RAI in this case.

[Max_Killjoy]

Seriously though, the time involved isn't relevant, because the real question is, do the rules state a general method for interrupting a spell being cast? Yes...but...only a spell with a casting time of greater than 1 Action.

There are specific exceptions of course, such as the oft referenced Counterspell. But this is a specific exception, and a core philosophy of 5e is that specific exceptions can break general rules. The general rules only state you can interrupt the casting of a spell with a casting time of greater than 1 Action. Specific exceptions exist that allow specific Reactions (like Counterspell) to interrupt casting. But that doesn't mean that any Reaction can interrupt, just the specific exceptions.

You're missing the point.

This entire thread has been rules-first, rules-forward, in a particular rubric it's a heavily Gamist. Even your answer right here goes right back to that.

Whereas for me, the basic question of this thread cannot be answered without knowing how long it takes, "in-fiction", for certain actions to occur. It matters how long it actually takes to cast a spell "in fiction", vs how long it takes to react and complete the interrupting attempt "in fiction". And no, that is not defined by Actions and Reactions and Bonus Actions and "specific exceptions".

As much as 5e has been touted as being more "fiction first" (not story, not narrative, "fiction layer"), this thread is strong evidence that either it's still the same old rules-first, disconnected system as all the other editions, or that the general D&D playerbase is reading it as rules-first because that's who the general D&D playerbase will always be.

[ProsecutorGodot]

Ah, the fate of forum threads! The original original idea was to figure out what are all the available ways to disrupt and negate a spell being cast, and here we have shifted to discussing the opposite; how to cast as many spells as possible!

Arguing over the time involved had to do with "real world common sense" attempts to justify breaking spell casting down further into steps which would present an opportunity to interrupt the casting by intervening in between steps (i.e. "beginning to cast" vs "finish casting").

I didn't realize at the time how much of a mistake it would be to answer that question. I believe Max_Killjoy was the first to argue that a time frame (that we apparently don't have) was necessary to reach an suitable conclusion, which I disagree with from a rules standpoint and attempted to disprove with an estimation of casting times (which we do have), even if I also pointed out that it was irrelevant to the original point of the thread.

Doesn't matter too much, both sides have their feet planted firmly in the ground, just about every relevant piece of information is already out there and now it's up to those interested to take it and shape their opinions with it.

You're missing the point.

This entire thread has been rules-first, rules-forward, in a particular rubric it's a heavily Gamist. Even your answer right here goes right back to that.

Whereas for me, the basic question of this thread cannot be answered without knowing how long it takes, "in-fiction", for certain actions to occur. It matters how long it actually takes to cast a spell "in fiction", vs how long it takes to react and complete the interrupting attempt "in fiction". And no, that is not defined by Actions and Reactions and Bonus Actions and "specific exceptions".

As much as 5e has been touted as being more "fiction first" (not story, not narrative, "fiction layer"), this thread is strong evidence that either it's still the same old rules-first, disconnected system as all the other editions, or that the general D&D playerbase is reading it as rules-first because that's who the general D&D playerbase will always be.
I think you're missing the point then, since a rules question requires a rules answer.

The fiction is facilitated by the rules (which you are also given the freedom to change on the fly) and generally you need to follow them to actually play the "game part" of DND (combat) and can be much looser with the "roleplay part" (everything else).

EDIT: To attempt to clarify with an example, since looking back at this it might seem a bit confrontational, if a DM is presented with a scenario outside of combat that might reasonably trigger the "rules heavy" combat structure that you appear to have issue with (again, I'm assuming here) then it would make sense for them to trigger such a combat or to better facilitate it by fiat. They could also decide to gloss over it, deciding that whatever outcome the player is trying to get is inevitable and simply chooses to allow that.

Example 1: Player wants to execute a downed enemy with a weapon attack. The DM could ask him to roll attack, but more likely a (in my opinion) reasonable DM would allow it to happen, describing how it happens and skipping over the attack/damage rolls entirely because at that time it doesn't make a whole lot of sense for the PC to fail.

Example 2: BBEG Wizard begins combat with a spell cast, Player asks DM if he can use a weapon attack as a reaction against it and DM says that initiative will be rolled and Player can act before this if he rolls initiative higher than BBEG.

[CorporateSlave]

... or that the general D&D playerbase is reading it as rules-first because that's who the general D&D playerbase will always be.

(Please excuse the omission of most of what you said, excerpt above for the sake of brevity and not deception.)

Probably this bit, although I suppose there will always be specific exceptions to the general D&D player base.:smallcool:

However, in all fairness to those of us interpreting it in a rules forward manner, the precise question (and indeed topic title) is "What ways are there to disrupt spellcasting in 5e?" which certainly at least implies they want to know what RAW game mechanics exist. Perhaps if the question had been framed more like "What are possible creative ways to disrupt spell casting?" or "What do you think ought to be able to interrupt a spell as it is being cast?" then breaking it down to what makes sense in a fantasy world simulation would be more applicable. But come to a forum asking a rules based question...


So preparing an action to attack when the enemy cast doesn’t work anymore. Are there feats or abilities that let you do it? (Other than counterspell)


...you're probably going to get some rules based answers.

The OP literally acknowledged he understood the "attack to disrupt spell casting" didn't exist in 5e, and asked if there were feats or abilities that would allow it. He wasn't even looking for ways to justify Reaction Attacks by breaking the spell down into imaginary (from a RAW point of view) steps. That only came later from other posters.

I believe you are correct that in order to answer that new question (could an imaginary magical spell somehow be interrupted depending on the speed and reflexes of the interrupting party), you would need to break everything down into the times involved. However, I don't see 5e as intending to get tied down in such convoluted combat mechanics, which to me is how it can focus more on the "fantasy first" rather than getting bogged in long and complicated combat as you figure out casting times and segments of the round and whatnot.

I mean, it's all made up, and intentionally simple. For all we know, "in the real world" casting a spell mostly takes place in the wizard's mind, with a final flourish, magic word, or brandishing of a component or focus. Without knowing that, you're right how can we say what would interrupt such an event? It just seems to me that 5e was developed to avoid such questions in the first place.


Hey, 5e was also developed with a "the DM can do what they want anyway" philosophy. But even beyond the RAW of the question, I feel (as in, my personal opinion is), allowing just about anything to disrupt a spell really steals the thunder from the few spells and abilities that do allow this according to the RAW. "Save your 9th level spell slot wizard! No need for Counterspell, when the Lich casts Wish our rogue will simply accomplish the same disruption with a 1/20th gp crossbow bolt!"

[Naanomi]

To summarize:

1) nothing about getting hit inherently disrupts spellcasting, regardless of timing (unconsciousness/death excepted)

2) there is a specific Ranger subclass ability that does disrupt spellcasting ‘in progress’, as well as the Counterspell spell

3) there are several spells/conditions that can prevent spellcasting in the first place but...

4) the exact timing allowances of triggering your readied action are nebulous, which ultimately means it is more or less up to the GM as to whether you can inflict one of those hampering conditions ‘mid spellcasting action’

5) some of the other, more narrative ways to prevent spellcasting (gagging, interfering with somatic components, etc) are even more deeply entrenched in DM fiat, and are not explicitly mentioned or references in existing rules anywhere

[PhoenixPhyre]

I agree with Corporate_Slave.

Highly "connected" rule-sets, especially about something as complex as combat, tend to be both complex themselves and tied to one particular set of "setting facts". Both of those are things that 5e does not want to do. 5e prizes simplicity and flexibility. Even things like Bonus actions and Reactions are themselves exceptions and are conditional. The developers have said that they did not want people to try to optimize their action economy. They don't want people worrying about things like specifying the reaction timing so as to get X result. Yes, this comes at the cost of having disconnected rules.

Being fiction-forward is a constraint on the space of possible rule sets. But it's not the only constraint. In combat, particularly, 5e has chosen simplicity and ease of resolution as its key goals, which inherently requires a higher level of abstraction (and thus "disconnection"). In addition, 5e wants to allow flexibility--the time involved for a spell being cast may differ between worlds. So specifying the exact timing details breaks the abstraction completely and causes lots more corner cases, while also removing any chance of flexibility.

Connected =/= good. Disconnected =/= bad. And vice versa for both of them. All games strike a balance between all the multitude of constraints.

[tieren]

I would like to add that there is a logical fallacy in relying on the existence of Counterspell to prove that it is possible to detect a spell mid cast.

Nothing in Counterspell gives the wizard the ability to detect a spell is being cast. Everyone implicitly agrees it doesn't work on subtle spells, so it is clear there must be some other perceivable phenomenon in order for the caster to realize a spell is being cast and to try to cast Counterspell. He doesn't even have time to try to notice what spell it is (only has one reaction).

Whatever that perceivable phenomenon is can be a trigger for a readied action (waves hands, says something, waves focus, whatever), but "begins to cast" is a meta construct that doesn't exist in game.

[Tanarii]

Whatever that perceivable phenomenon is can be a trigger for a readied action (waves hands, says something, waves focus, whatever), but "begins to cast" is a meta construct that doesn't exist in game.
It's also worth noting that a V, S or M component is clearly perceivable as specifically a V, S or M component. Since only they can trigger a Counterspelling. Waving hands or saying something cannot.

[ProsecutorGodot]

It's also worth noting that a V, S or M component is clearly perceivable as specifically a V, S or M component. Since only they can trigger a Counterspelling. Waving hands or saying something cannot.

That's the issue, Counterspell is specific in it's function and people are taking it's use in this way as a proof that those motions are objectively apparent to the character with zero degree of doubt.

As an example, it's kind of like claiming that the fact that Hold Person can only be cast on a humanoid is proof positive that attempting to cast Hold Person on something and having it fail is automatically going to connect to your character that the target was not a humanoid. The player might be aware of the difference depending on how the DM handles this, but your character shouldn't (and can't) know whether the spell failed to take effect for that reason or a number of other reasons.

These specific rules limitations are present for mechanical purposes, disconnected from the in-world logic.

[NaughtyTiger]

Keep in mind movement is not an action in this edition. It is not indivisible by default.

Actions are not indivisible by default either. (Too many negatives) Actions can be divisible by default. The PHB is silent on this. (unless you got pg number i missed)
Crawford was perfectly okay with the attack action being divisible for 3 years. Then he wasn't.



Ie doesn't even have time to try to notice what spell it is (only has one reaction).
Whatever that perceivable phenomenon is can be a trigger for a readied action (waves hands, says something, waves focus, whatever), but "begins to cast" is a meta construct that doesn't exist in game.

XtgE's optional rule:
if the DM does not use the optional rule, then yes, the Counterspeller has time to notice what spell it was (and may notice without a check).
If the DM does use the optional rule, then yes, someone can take a reaction to identify a spell then is beginning to be cast AND communicate what that spell is to another caster to take a reaction to stop that spell. (Time enough for 2 chained reactions that independently require noticing "begins to cast".

[Unoriginal]

It's also worth noting that a V, S or M component is clearly perceivable as specifically a V, S or M component. Since only they can trigger a Counterspelling. Waving hands or saying something cannot.

This is incorrect.

It's all a question of perception. If the Bard decides to fake casting a spell, it'd be a CHA (Deception) check, and a caster could try to Counterspell it if they're fooled by it.

It just has no effect. Same way that if you Ready a Heat Metal spell to cast on the first enemy in full plate that approach, you still cast it if a Doppleganger looking like a knight in armor charges at you, even though it won't have any effect because the "armor" isn't metal (assuming you're fooled by the disguise).

[NaughtyTiger]

This is incorrect.

It's all a question of perception. If the Bard decides to fake casting a spell, it'd be a CHA (Deception) check, and a caster could try to Counterspell it if they're fooled by it. .

This is incorrect.

Counterspell specifies the trigger "1 reaction, which you take when you see a creature within 60 feet of you casting a spell", not "within 60 feet of you that you think is casting a spell"

Yours is a perfectly reasonable houserule, and one that I like in my experience, but it is not in the rules.

[Naanomi]

And solving the perception issue doesn’t address the whole problem of timing... what if I had Detect Thoughts going? Could I ready an action for ‘when they think about casting a spell’ that happens before the spell is actually cast? The parsing issue of whether there is a window between ‘going to do X’ and ‘doing X’ that can be responded to still exists

[Unoriginal]

This is incorrect.

Counterspell specifies the trigger "1 reaction, which you take when you see a creature within 60 feet of you casting a spell", not "within 60 feet of you that you think is casting a spell"

Yours is a perfectly reasonable houserule, and one that I like in my experience, but it is not in the rules.

Let's see what the actual rules say:


INVALID SPELL TARGETS
A spell specifies what a caster can target with it: any type of creature, a creature of a certain type (humanoid or beast, for instance), an object, an area, the caster, or something else. But what happens if a spell targets something that isn’t a valid target? For example, someone might cast charm person on a creature believed to be a humanoid, not knowing that the target is in fact a vampire. If this issue comes up, handle it using the following rule.

If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect on a target that succeeds on a saving throw, the invalid target appears to have succeeded on its saving throw, even though it didn’t attempt one (giving no hint that the creature is in fact an invalid target). Otherwise, you perceive that the spell did nothing to the target.

You can waste your spell slot and your reaction trying to Counterspell something that is not a valid target for Counterspell, the same way you can waste your action and your spell slot trying to Charm Person a disguised Rakshasa.

Invalid target does not mean "you can't do it, the spell choke in your throat and your spell slot is saved", it means "your spell has no effect if it's not the proper target."

Giving spellcasters the inherent capacity to never miss-target something is a major boost of their powers (perhaps not ridiculously overpowered, but still ridiculous, given you could foil all attempts at deception just by having a cantrip that target the real thing be unable to target the deception attempt).


And solving the perception issue doesn’t address the whole problem of timing... what if I had Detect Thoughts going? Could I ready an action for ‘when they think about casting a spell’ that happens before the spell is actually cast? The parsing issue of whether there is a window between ‘going to do X’ and ‘doing X’ that can be responded to still exists

There is no problem of timing. Either the specific reaction lets you do it before the trigger is finished, or it goes by the default "once the trigger is finished (aka the whole action/reaction/bonus action), the reaction happens".

[NaughtyTiger]

Let's see what the actual rules say:




A spell specifies what a caster can target with it: any type of creature, a creature of a certain type (humanoid or beast, for instance), an object, an area, the caster, or something else. But what happens if a spell targets something that isn’t a valid target? For example, someone might cast charm person on a creature believed to be a humanoid, not knowing that the target is in fact a vampire. If this issue comes up, handle it using the following rule.

If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect on a target that succeeds on a saving throw, the invalid target appears to have succeeded on its saving throw, even though it didn’t attempt one (giving no hint that the creature is in fact an invalid target). Otherwise, you perceive that the spell did nothing to the target.


Indeed. Casting a spell burns a slot. But I didn't see in that quote where you can use a Reaction to do something that isn't Triggered.
Cuz snap, I think he is moving out of range, I get an opportunity attack!

Seriously, though, we do allow deception as an action for the purpose of faking a spell, cuz it's a reasonable houserule.

[Unoriginal]

[QUOTE=Unoriginal;23789128]Let's see what the actual rules say:

[QUOTE]INVALID SPELL TARGETS
A spell specifies what a caster can target with it: any type of creature, a creature of a certain type (humanoid or beast, for instance), an object, an area, the caster, or something else. But what happens if a spell targets something that isn’t a valid target? For example, someone might cast charm person on a creature believed to be a humanoid, not knowing that the target is in fact a vampire. If this issue comes up, handle it using the following rule.

If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect on a target that succeeds on a saving throw, the invalid target appears to have succeeded on its saving throw, even though it didn’t attempt one (giving no hint that the creature is in fact an invalid target). Otherwise, you perceive that the spell did nothing to the target.

Indeed. Casting a spell burns a slot. But I didn't see in that quote where you can use a Reaction to do something that isn't Triggered.

So according to you, if someone uses a Major Image to make it look like a summoned Demon is charging past the Fighter with Sentinelle to "attack" the squishy members of the group, and the Fighter says "I use my Reaction to AoO this Demon, hopefully I can get its movement to 0", the DM would say "no, you can't, it's not actually a valid trigger" unless they're houseruling ?

[NaughtyTiger]

So according to you, if someone uses a Major Image to make it look like a summoned Demon is charging past the Fighter with Sentinelle to "attack" the squishy members of the group, and the Fighter says "I use my Reaction to AoO this Demon, hopefully I can get its movement to 0", the DM would say "no, you can't, it's not actually a valid trigger" unless they're houseruling ?

No, I am saying "According to the rules, If some... they are houseruling" :)
House rule or at least a ruling, but I don't believe ineligible triggers are covered by RAW.

[patchyman]

If I were te DM, I'd just rule what makes sense to me. And to be honest, interrupting a spell should be allowed under certain circumstances with the ready action. An action takes six seconds and so does casting most spells. I don't see a reason not to allow it at my table if they word there rdy action correctly and their plan seems plausible.

The way I’d rule it is that I probably would not let damage disrupt the spell unless it already was a concentration spell subject to disruption, but I would allow actions that could prevent one of the requirements of the spell going off, like gagging the caster in mid-spell.

[tieren]

I don't believe ineligible triggers are covered by RAW.

Thats a fair statement, but to suggest that anyone who rules the other way is violating RAW is wrong.

Its the same poor logic that results in warlocks trying to eldritch blast every chest to see if its an object or a mimic (EB can only target creatures).

[NaughtyTiger]

Thats a fair statement, but to suggest that anyone who rules the other way is violating RAW is wrong.


Unoriginal is a proponent of if it isn't in the book it isn't RAW. (long threads about what is RAW) So if you interpret something that isn't explicitly in the text, then you are not following Rules as Written (int the text).

And when he condescendingly points to a rule that doesn't disprove me, I get to gloat a little.

[ProsecutorGodot]

Unoriginal is a proponent of if it isn't in the book it isn't RAW. (long threads about what is RAW) So if you interpret something that isn't explicitly in the text, then you are not following Rules as Written (int the text).

And when he condescendingly points to a rule that doesn't disprove me, I get to gloat a little.

Wow, I don't think that's called for in the slightest. Especially since you're the one throwing "Houserule" and "it's not RAW" around.

[patchyman]

An issue I have with the 'when they reach for the spell component pouch' is that until they grab it how do you know that that's what they were doing, especially if they have multiple items on their belt. Secondly there is no defined order of operations to cast a spell, like it could be focus on the magic, wave hands, say words, grab pouch or any other order.

Is this really an issue though? If my character is in combat, skips an attack to Ready an action “when the guy in the back in robes looks like he starts to cast a spell”.

On his turn, the DM says “he begins to say something” or “he reaches for something on his belt”. By the definition of the Ready action, I can either use my readied action or let it go to waste. It is my choice as a player to interpret what the DM has described, as it always is.

Maybe I’m right, maybe I’m wrong, maybe the DM is a jerk, but in all cases, it’s my call based on what the DM has described.

[Max_Killjoy]

This is incorrect.

Counterspell specifies the trigger "1 reaction, which you take when you see a creature within 60 feet of you casting a spell", not "within 60 feet of you that you think is casting a spell"

Yours is a perfectly reasonable houserule, and one that I like in my experience, but it is not in the rules.

So having Counterspell gives a character the ability to detect that an actual spell is being cast? With 100% accuracy?

[patchyman]

Whatever that perceivable phenomenon is can be a trigger for a readied action (waves hands, says something, waves focus, whatever), but "begins to cast" is a meta construct that doesn't exist in game.

I would agree to the only to the extent that the same rules apply to Counterspell ie that a wizard could attempt (and fail) to counterspell based on the mistaken impression that another caster was casting a spell.

[Man_Over_Game]

Been reading a lot of this thread, but I keep pondering the same thing that isn't getting much attention.

Question to Everybody: What's fair?

Is it fair for someone to spend a level 3 spell slot (Counterspell) to have it be wasted with no effect?
Counterspell can already fail against higher level spells, and already has a risk of gambling too high/low of a Counterspell level. On the flipside, Counterspell is reliable at removing high level spells at a very low cost, and as long as the target caster wasted an action to "pretend" to cast a spell, I guess I don't see a problem with it. Although, I'd rather like to see an Arcana Check built in to determine the information about the spell being cast, before the Counterspell is released. That'd be the perfect solution, IMO, rewarding players for their investments and being able to see through enemy schemes outside of meta decision making.

Meta planning shouldn't take precedence over in-character abilities, so if tricking people was an option, there needs to be an in-character, stat-based solution. Much like Illusions vs. Passive Investigation.

Is it fair for a martial class to interrupt a caster's process of casting a spell?
Casters can already cripple melee combatants. How do you like that Heat Metal or Wall of Force?
As long as there is ample risk from Readying an Action (like losing your focus due to taking damage, like Concentration, causing you to lose the attack for the turn?), I don't inherently see a problem with it. My main concern is that characters should be allowed to play, and rarely should be told "No", and the only times a "No" effect should come from a character is when it comes with some kind of high cost/risk (like with casting a Save or Suck spell, like Tasha's Hideous Laughter. Something low-risk that says "No" needs to be very expensive, like Forcecage).

A lot of people are focusing on the semantics to determine what's legal, but that's not going to improve the game as a whole. I'd like to hear what you guys have to say about it being an active choice to decide how things should be.

[Unoriginal]

Is it fair for someone to spend a level 3 spell slot to have it be wasted with no effect?

Yes, absolutely.

It doesn't matter if you're using a 3rd level spell slot, if you cast Fireball at an Efreeti you're wasting it.

And that is ok. Casters can and will do mistakes. That's part of what makes them far better characters that the shallow this-caster-is-prepared-for-everything-and-always-has-the-solution unintentional parodies that you often see brought up in forum discussions.



Is it fair for a martial class to interrupt a caster's process of casting a spell?


If it's a specific power of the class? It's fair.

If it's something everyone can attempt? No, it is not.

The capacity to interrupt the casting of a spell is rare and costly. The Monster Hunter Ranger can do it as one of their signatures move, and the limits of Counterspell have been covered already. Authorizing anyone to do it at no cost diminishes both enormously.

[ProsecutorGodot]

Been reading a lot of this thread, but I keep pondering the same thing that isn't getting much attention.

Question to Everybody: What's fair?

Is it fair for someone to spend a level 3 spell slot (Counterspell) to have it be wasted with no effect?
Counterspell can already fail against higher level spells, and already has a risk of gambling too high/low of a Counterspell level. On the flipside, Counterspell is reliable at removing high level spells at a very low cost, and as long as the target caster wasted an action to "pretend" to cast a spell, I guess I don't see a problem with it. Although, I'd rather like to see an Arcana Check built in to determine the information about the spell being cast, before the Counterspell is released. That'd be the perfect solution, IMO, rewarding players for their investments and being able to see through enemy schemes outside of meta decision making.

Meta planning shouldn't take precedence over in-character abilities, so if tricking people was an option, there needs to be an in-character, stat-based solution. Much like Illusions vs. Passive Investigation.

Is it fair for a martial class to interrupt a caster's process of casting a spell?
Casters can already cripple melee combatants. How do you like that Heat Metal or Wall of Force?
As long as there is ample risk from Readying an Action (like losing your focus due to taking damage, like Concentration, causing you to lose the attack for the turn?), I don't inherently see a problem with it. My main concern is that characters should be allowed to play, and rarely should be told "No", and the only times a "No" effect should come from a character is when it comes with some kind of high cost/risk (like with casting a Save or Suck spell, like Tasha's Hideous Laughter. Something low-risk that says "No" needs to be very expensive, like Forcecage).

A lot of people are focusing on the semantics to determine what's legal, but that's not going to improve the game as a whole. I'd like to hear what you guys have to say about it being an active choice to decide how things should be.

There's also the side of "is it fair to the caster's who spend these spell slots to be outdone by a Barbarian with a backpack full of pointy sticks" and the answer is "In most cases no, but in some cases we should make exceptions like how mage slayer does almost nothing to actually make you more effective at slaying mages."

I agree on principle that characters should be enabled to do what they plan to do, but the DM has to facilitate that within the rules. I would be pretty fed up with a player who tried to make a regular occurence out of using readied actions in this way, expecting it to work with 100% accuracy when the Wizard has spent the last 3 sessions rolling terribly on crucial counterspell checks. The Wizard isn't going to think this is very fair.

So I guess in short: Your DM decides what's fair, using the rules.

[Max_Killjoy]

Been reading a lot of this thread, but I keep pondering the same thing that isn't getting much attention.

Question to Everybody: What's fair?

Is it fair for someone to spend a level 3 spell slot (Counterspell) to have it be wasted with no effect?
Counterspell can already fail against higher level spells, and already has a risk of gambling too high/low of a Counterspell level. On the flipside, Counterspell is reliable at removing high level spells at a very low cost, and as long as the target caster wasted an action to "pretend" to cast a spell, I guess I don't see a problem with it. Although, I'd rather like to see an Arcana Check built in to determine the information about the spell being cast, before the Counterspell is released. That'd be the perfect solution, IMO, rewarding players for their investments and being able to see through enemy schemes outside of meta decision making.

Meta planning shouldn't take precedence over in-character abilities, so if tricking people was an option, there needs to be an in-character, stat-based solution. Much like Illusions vs. Passive Investigation.

Is it fair for a martial class to interrupt a caster's process of casting a spell?
Casters can already cripple melee combatants. How do you like that Heat Metal or Wall of Force?
As long as there is ample risk from Readying an Action (like losing your focus due to taking damage, like Concentration, causing you to lose the attack for the turn?), I don't inherently see a problem with it. My main concern is that characters should be allowed to play, and rarely should be told "No", and the only times a "No" effect should come from a character is when it comes with some kind of high cost/risk (like with casting a Save or Suck spell, like Tasha's Hideous Laughter. Something low-risk that says "No" needs to be very expensive, like Forcecage).

A lot of people are focusing on the semantics to determine what's legal, but that's not going to improve the game as a whole. I'd like to hear what you guys have to say about it being an active choice to decide how things should be.

See, that's a lot closer to where I'm coming from.

Overall, this discussion, and its overall focus on inane quibbling over RAW instead of trying to figure out what makes sense and makes for a better RPG experience at the table, is exactly the sort of thing that drove me away from all things D&D 20-some years ago.

[Unoriginal]

like how mage slayer does almost nothing to actually make you more effective at slaying mages."

Mage Slayer lets you hit mages more if they try using magic. It's not "almost nothing", IMO, but I've seen people agree with your bluetext.

[Man_Over_Game]

like how mage slayer does almost nothing to actually make you more effective at slaying mages.

I am actually very confused about this blue text.

Is this a problem you think is true? Are you poking fun at people who feel that this is true? Do you think this is true but want to avoid an argument so you're bluetexting it so it's played off as a joke?

Very confused.

[ProsecutorGodot]

Mage Slayer lets you hit mages more if they try using magic. It's not "almost nothing", IMO, but I've seen people agree with your bluetext.

Very confused.

It's mostly aimed at the very specific scenario where the caster is going to be able to Teleport before your reaction attack goes off, the oft used "White Room Scenario" that people use to universally discredit this feat. While it does work that way with a straight reading, I'd be more willing to make exceptions if a player has invested in this feat, rather than when a player is trying to emulate this feat with clever words.

It generally does quite a bit in helping you slay mages, giving them disadvantage on a concentration check by itself is a powerful feature in my opinion. I don't personally think that it's a bad feat.

[Tanarii]

Mage Slayer lets you hit mages more if they try using magic. It's not "almost nothing", IMO, but I've seen people agree with your bluetext.
Also helps protect you against certain of their magics when you get up close and personal, and helps disrupt certain magics when you hit them.

Personally I like its not an auto "I win" button vs casters, like some people seem to want.


It's mostly aimed at the very specific scenario where the caster is going to be able to Teleport before your reaction attack goes off.
Yeah I can see where thats a little frustrating. :smallamused:

[Unoriginal]

It's mostly aimed at the very specific scenario where the caster is going to be able to Teleport before your reaction attack goes off. I'd be more willing to make exceptions if a player has invested in this feat, rather than when a player is trying to emulate this feat with clever words.

It generally does quite a bit in helping you slay mages, giving them disadvantage on a concentration check by itself is a powerful feature in my opinion.

Rule of thumb for me: if you think your clever words can replicate a feat or a class feature, they're not actually that clever.


Plenty of things can be emulated, though in more difficult and/or less effective ways.

[Aquillion]

Rule of thumb for me: if you think your clever words can replicate a feat or a class feature, they're not actually that clever.

Plenty of things can be emulated, though in more difficult and/or less effective ways.Mage Slayer doesn't require that you spend an action to ready an attack. Readied Actions do, of course!

I'm not sure why people are confused on this point. There's no reason to even bring Mage Slayer up, since clearly it offers a massive advantage over using Ready Actions the way people have outlined in this thread.

Nobody, as far as I'm aware, is suggesting that you can prevent a spell with a Readied Action unless you actually have some ability that would change the situation to make the spell impossible, eg. casting Silence. And those tend to be even more costly, since you have to risk a spell slot when you ready it. You seem to be fixated on answering a question - "can you ready an action to hit someone in order to cancel their spell" - which nobody is asking, since everyone is clear that just hitting them will only prevent them from casting if it actually kills them.

So I'm not sure why you brought up Mage Slayer at all.

[ProsecutorGodot]

Mage Slayer doesn't require that you spend an action to ready an attack. Readied Actions do, of course!

I'm not sure why people are confused on this point. There's no reason to even bring Mage Slayer up, since clearly it offers a massive advantage over using Ready Actions the way people have outlined in this thread.
One of the reasons that Mage Slayer is at least relevant for comparison is that the most hotly debated part of this isn't even to use the Readied Action to emulate Mage Slayer exactly (which, again and again ad nauseam I repeat that I find to be acceptable in some cases) but they're trying to use Readied Action in a way that is decidedly more effective than the Mage Slayer feat is allowed to be. It's more effective than Counterspell.

I think it's a flimsy argument if "action and reaction" is weighted on the same tier as "3rd level spell slot and reaction" or "I took this feat with one of my limited ASI just to have this reaction".


since everyone is clear that just hitting them will only prevent them from casting if it actually kills them.
Not everyone is clear that you're able to even use Readied Action in this way, there are so many signs pointing towards "No" that I would generally (again, to repeat, that there are exceptions) not allow "when they begin casting a spell" to be a suitable trigger.

[Unoriginal]

Mage Slayer doesn't require that you spend an action to ready an attack. Readied Actions do, of course!

I'm not sure why people are confused on this point. There's no reason to even bring Mage Slayer up, since clearly it offers a massive advantage over using Ready Actions the way people have outlined in this thread.

Nobody, as far as I'm aware, is suggesting that you can prevent a spell with a Readied Action unless you actually have some ability that would change the situation to make the spell impossible, eg. casting Silence. And those tend to be even more costly, since you have to risk a spell slot when you ready it. You seem to be fixated on answering a question - "can you ready an action to hit someone in order to cancel their spell" - which nobody is asking, since everyone is clear that just hitting them will only prevent them from casting if it actually kills them.

Several persons have defended that hitting people mid-cast would at least have a chance to stop the casting.



So I'm not sure why you brought up Mage Slayer at all.

I wasn't the one who brought it up.

[Misterwhisper]

It's mostly aimed at the very specific scenario where the caster is going to be able to Teleport before your reaction attack goes off, the oft used "White Room Scenario" that people use to universally discredit this feat. While it does work that way with a straight reading, I'd be more willing to make exceptions if a player has invested in this feat, rather than when a player is trying to emulate this feat with clever words.

It generally does quite a bit in helping you slay mages, giving them disadvantage on a concentration check by itself is a powerful feature in my opinion. I don't personally think that it's a bad feat.

It is not a "very specific" scenario it is quite an extensive list of spells that ignore mage slayer completely.

Shocking Grasp
Darkness
Fog cloud
Hold Person
Invisibility
Greater Invisibility
Charm Person or any spell with the charm effect
Sleep
color spray
Hideous Laughter
Blindness
Misty Step
Suggestion maybe depending on what you suggest
Dominate person
power word stun
power word kill
Wall of stone
wall of force
Flesh to stone
Force Cage - the instant lose button to all melee characters
Polymorph other
Time Stop

Those are just off the top of my head and just spells on the wizard list in the PHB

A caster does not have to know that you have the feat to protect against it, any smart caster is going to assume their enemies have it and act accordingly.

If you are standing in their face with a melee weapon in your hand why would they cast fireball or lightning bolt when they could just cast darkness and leave you standing there, or force cage and take you out of the fight 100% of the time.

[ProsecutorGodot]

It is not a "very specific" scenario it is quite an extensive list of spells that ignore mage slayer completely.

Why am I so thoroughly unable to write a sentence without spelling out every conceivable exception.

Replace "Teleport" with any spell you listed and any spell, feature, fruit, animal you didn't list. It doesn't change what my point was.

Thank you for your extensive listing of effects that prevent you from using the reaction granted from Mage Slayer.

[CorporateSlave]

A lot of people are focusing on the semantics to determine what's legal, but that's not going to improve the game as a whole. I'd like to hear what you guys have to say about it being an active choice to decide how things should be.


The OP asked about RAW ways (feats or abilities) to disrupt spell casting other than Counterspell. He was asking a rules question, not a philosophical "how to improve the game" question. However, since you have asked that question, I shall answer it to the best of my opinion: In fact, that's sort of why I wrote this bit earlier on:



Hey, 5e was also developed with a "the DM can do what they want anyway" philosophy. But even beyond the RAW of the question, I feel (as in, my personal opinion is), allowing just about anything to disrupt a spell really steals the thunder from the few spells and abilities that do allow this according to the RAW. "Save your 9th level spell slot wizard! No need for Counterspell, when the Lich casts Wish our rogue will simply accomplish the same disruption with a 1/20th gp crossbow bolt!"

I don't think going against the RAW in this case is remotely fair, and I don't think it improves the game, in fact I think it spoils some of it (by effective removing a lot of the value from things like Counterspell) and potentially cripples caster classes. How? Well, if I were DM, only the dumbest of monsters would not have someone(s) Readying an Attack to shoot or stab a PC caster every single time they cast a spell. Because if we're going "in game real world logic" in a world with magic where its as easy as any well timed arrow to potentially disrupt a spell's casting, the various populations would have figured this out a long time ago and it would be a standard combat practice. Only an idiotic militia/army/gang/clan wouldn't have a few bowmen trained to know what "starting to cast a spell" looks like, and to hold their shots until they see it taking place. Awww..is that being a mean DM? I guess enemy wizards shouldn't have access to Counterspell either? The same rules and tactics apply to NPC enemies and PCs alike.

It certainly would be an insane power boost to Subtle Spell! Not to mention making War Caster and Resilient CON essentially a double "Feat tax" on casters (assuming a CON check would be called for to avoid the disruption, similar to how longer casting time spells are actually handled in the RAW), if they want any chance of spells firing off in combat.

You can complain about trying to stick to RAW, but just maaaybe the game designers wrote it that way as a game balance device? I've seen plenty of house rulings that "fixed" some aspect of the 5e that actually ended up ruining the campaign with PC power creep, and it ended up being un-fun for everybody. That's not to say the designers got everything right...but after all "right" can be pretty subjective when it comes to game mechanics.

[NaughtyTiger]

Wow, I don't think that's called for in the slightest. Especially since you're the one throwing "Houserule" and "it's not RAW" around.
which part is uncalled for?

House rule is not an insult.
RAW is not an praise.

It is that I hold Unoriginal to his own definition of RAW?

If it's not written, it is not RAW, by definition. Your friend's definition was not correct.
But it's not because it's not RAW that it doesn't exist.

It is that I thought "Let's see what the actual rules say" was condescending?


So having Counterspell gives a character the ability to detect that an actual spell is being cast? With 100% accuracy?

Unless you can point to a rule in PHB or DMG that says otherwise, then per Rules as Written, yes.

Does that mean that a DM is wrong for adding a method for Counterspell to be wrong? Not at all.
In fact, my stance in the referenced thread is that it is RAW unless specifically prohibited, cuz DM makes the rules is the first rule...

[Max_Killjoy]

Unless you can point to a rule in PHB or DMG that says otherwise, then per Rules as Written, yes.


That seems more "rules as implied" or "rules as inferred".

How is it RAW if it's not Written in the Rules?

[ProsecutorGodot]

which part is uncalled for?

Well with the additional context here, it's more or less taking a personal beef from a previous thread and continuing it here. You also (in my opinion) are misrepresenting their stance because the way you described it does not convey what I read from their posts.


Unless you can point to a rule in PHB or DMG that says otherwise, then per Rules as Written, yes.

Does that mean that a DM is wrong for adding a method for Counterspell to be wrong? Not at all.
In fact, my stance in the referenced thread is that it is RAW unless specifically prohibited, cuz DM makes the rules is the first rule...

Make careful note that "character" is being used in this question. The player might be aware that Counterspell is being used appropriately, the character isn't guaranteed to know anything.

If it's not written, it's not RAW. If there's no proof for something to exist (such as a "casting" phase of spells that exists outside of applicable reactions) then it's not RAW. That's how that phrase is defined, whether you like the phrase or not, it is recognized that way by the game designers.


That seems more "rules as implied" or "rules as inferred".

How is it RAW if it's not Written in the Rules?
I agree with this, this seems to be what you're basing your definition off of.