Reaction Spells

[Seatbelt]

So this came up at my Adventurer's Society game. One of the players attacks an NPC wizard, he casts shield, causing the attack to miss. My ruling is that the shield negates the hit before damage is dealt. But the wording on the spell is something line "after a hit, as a reaction..." and one of the players thought that meant that after the hit and thus damage dealt, the wizard may cast the spell.

So which is it?

[DivisibleByZero]

The DMG tells us that reactions happen after the trigger is finished, unless specified otherwise. If it is uncertain, it happens after.
The PHB tells us that some reactions can interrupt, and then the creature can continue its turn after the interruption. When a reaction is an interrupt, there is always text to tell us so (but not in those words).
The shield spell specifies that it applies to the attack that triggered it, so it is an interrupt.
There is a whole thread arguing Mage Slayer on this page where you can see people arguing the differences between interrupts and merely reactions if you want to dive in and see a whole lot of pointless arguing, but in that thread you'll clearly see that shield interrupts the attack and happens before the damage occurs.

[Safety Sword]

The Shield spell is a special case and the boundaries of the case is outlined in the spell description.

It is one of the few spells that can modify your Armour Class after an attack roll's outcome has been determined to change whether the attack was in fact a hit at all.

It adds +5 to AC, so if your new armour class would cause the attack roll to miss, then it is a miss.

Hope this helps.

[D.U.P.A.]

So for example, if you have AC 18 and the DM announced the attack score was 20, are you still eligible to use shield or you must say before DM says the number?

[Yagyujubei]

So for example, if you have AC 18 and the DM announced the attack score was 20, are you still eligible to use shield or you must say before DM says the number?

you can still do it, if the DM doesn't want you to know the attack that was rolled then he better just not say it. really, he should wait for YOU to say if you want to use your reaction or not. If he just steamrolls through it without thinking then it's his bad if you ask me.

[Chronos]

The DM shouldn't be announcing the roll was a 20. He should just be announcing that it was a hit. Then you say "I cast Shield. Is it still a hit?".

[Xetheral]

The DM shouldn't be announcing the roll was a 20. He should just be announcing that it was a hit. Then you say "I cast Shield. Is it still a hit?".

Whether or not the DM announces the total of the enemy's attack roll is very much a question of DM style. I don't feel there is any "should" or "shouldn't" involved--both approaches have their merits and their drawbacks.

[Safety Sword]

Whether or not the DM announces the total of the enemy's attack roll is very much a question of DM style. I don't feel there is any "should" or "shouldn't" involved--both approaches have their merits and their drawbacks.

Very much this. Many DMs, myself included don't like to say what I roll, and I roll behind a screen.

I have my player's ACs written down, so I know whether normally it would be a hit. I inform the player that their character has been hit, if they want to use their reaction they can do so.

This way has the advantage that the player doesn't always know whether it's a good time to try a shield spell. I don't like the meta-gaming that allows players to use shield only when it would benefit them most by knowing the enemy attack roll. But as Xetheral says, it's a particular DMing style. Not everyone will agree with any or all of that method.

[Yagyujubei]

well, my point was that a DM shouldn't be like "oh well I said it was a 20, so because i said it you can no longer use the spell" either you don't say the to hit, or you do. that's your call, but don't make it into some can the PC's be fast enough to interrupt me and say "SHIELD" before i blurt out the what the enemy rolled.

that seems contrived to me.

[Safety Sword]

well, my point was that a DM shouldn't be like "oh well I said it was a 20, so because i said it you can no longer use the spell" either you don't say the to hit, or you do. that's your call, but don't make it into some can the PC's be fast enough to interrupt me and say "SHIELD" before i blurt out the what the enemy rolled.

that seems contrived to me.

I wasn't suggesting that at all. I was suggesting that I say "The orc slashes at you with his mighty axe and it hits you".

The player, sings out: "I use my reaction to cast Shield"

I add 5 to their AC and describe whether or not the barrier that springs up intercepts the attack or not.

There's no time limit on the reaction being called as long as I haven't moved on to the next player or NPC in the initiative order.

[Knaight]

This way has the advantage that the player doesn't always know whether it's a good time to try a shield spell. I don't like the meta-gaming that allows players to use shield only when it would benefit them most by knowing the enemy attack roll. But as Xetheral says, it's a particular DMing style. Not everyone will agree with any or all of that method.

Honestly, I wouldn't necessarily call that metagaming. From a spear-fighting background, I'll say that it's often pretty easy to tell the difference between an incoming strike that might slip through your defenses but that you probably could have avoided by just being marginally faster (which the shield spell would block, in D&D terms), and the case where everything is going south really fast and you're in the position of some sort of desperate last-ditch get out of the way situation where the odds aren't good. There's still some uncertainty, but that's just real life being messy.

There's a case to be made for shield being variable. If it adds +1d8 to AC, then there's an interesting choice. Do you use it now, when you're in desperate last-ditch get out of the way territory and need to roll a +7 or higher, or save the spell for later when you need a +2 or +3?

[Xetheral]

There's a case to be made for shield being variable. If it adds +1d8 to AC, then there's an interesting choice. Do you use it now, when you're in desperate last-ditch get out of the way territory and need to roll a +7 or higher, or save the spell for later when you need a +2 or +3?

I like that! Although I might go with 1d10, as an apology to the poor wizard.

[Dexam]

I like that! Although I might go with 1d10, as an apology to the poor wizard.

I'd make it +2d4. That way you get an average of +5 (same as Shield), and a curve of probable bonuses instead of a flat line.

[Dimcair]

Honestly, I wouldn't necessarily call that metagaming. From a spear-fighting background, I'll say that it's often pretty easy to tell the difference between an incoming strike that might slip through your defenses but that you probably could have avoided by just being marginally faster (which the shield spell would block, in D&D terms), and the case where everything is going south really fast and you're in the position of some sort of desperate last-ditch get out of the way situation where the odds aren't good. There's still some uncertainty, but that's just real life being messy.


That.

Ever got a foot/tennis/volley/basket/baseball flying straight to your head? You will know before it hits you that it will, in fact, hit you good. Its taking up a spellslot, I dont see the need to take that away from the poor squishy wizard. After all a person bearing a shield does know too if it can or cannot block a blow fast enough with its shield.

[Safety Sword]

That.

Ever got a foot/tennis/volley/basket/baseball flying straight to your head? You will know before it hits you that it will, in fact, hit you good. Its taking up a spellslot, I dont see the need to take that away from the poor squishy wizard. After all a person bearing a shield does know too if it can or cannot block a blow fast enough with its shield.

Many many feet, and fists.

You're not taking anything away from the wizard. They have the choice to use the spell and slot, or not.

And the person with the shield doesn't have a chance to add +5 to AC with their reaction either...

[Dimcair]

Many many feet, and fists.

You're not taking anything away from the wizard. They have the choice to use the spell and slot, or not.

And the person with the shield doesn't have a chance to add +5 to AC with their reaction either...


No, the person with the shield has a +2 to AC permanently, because it is considered and assumed it knows how to use its shield.
You are taking the option from the wizard to use its one-time shield in a useful way.

I don't see the need to be stingy here and would allow him to make the most out of his spell-slot. If you disagree, fine, but do not pretend you are not taking away anything^^.

[D.U.P.A.]

The DM shouldn't be announcing the roll was a 20. He should just be announcing that it was a hit. Then you say "I cast Shield. Is it still a hit?".

It is hard to know everyone AC, especially if you are buffed with spells like Shield of faith, then having some cover, plus taking the dodge and then a DM said that the goblin hits, which could hit only with critical. Also is more fun for DM to say how much was total, because this way you are not feeling cheated like if you are constantly being hit by weak creatures while being quite heavily armored.

[coredump]

That.

Ever got a foot/tennis/volley/basket/baseball flying straight to your head? You will know before it hits you that it will, in fact, hit you good. Its taking up a spellslot, I dont see the need to take that away from the poor squishy wizard. After all a person bearing a shield does know too if it can or cannot block a blow fast enough with its shield.
Not the same thing. Yes you know the incoming attack is on target, but that is before you have taken defensive measures to get out of the way and/or block/parry the attack. It is usually pretty difficult to tell if the attack will actually hit, or if you will manage to avoid it. Using the Shield spell is like saying "I'm not taking any chances... I want help avoiding this attack."


I don't really care which method is used, but most of the dice-changing mechanics are set up to modify the roll *before* knowing the details.

[Dimcair]

Yes you know the incoming attack is on target, but that is before you have taken defensive measures.


Yup, then you react and use that reaction to raise your hands to avoid the football to the head. Or just to dodge if its too late to catch/block the football.

Not to argue that rules wise it is correct to resolve these things without details, all I am saying is that it makes sense in this case to give the Wizard that info without being overly concerned.

[Mandragola]

Real life considerations are tricky. In real life, if you see a blow coming you can get out of the way - and if you don't see it you can't do anything about it. How shield is supposed to work in this setting is tricky to understand really. How is it that you see a blow coming and have enough time to cast a spell - but not enough time to get out of the way or block? Maybe that makes sense with a fireball or something but less so with a sword swing.

There are a couple of abilities that require the DM to tell you either what he's rolled to hit or the total AC he's hit. Shield tells the DM to tell you what AC he hits. The valour bard inspiration effect tells him to say what he rolled but not what number he reached. It would be entirely possible to have a situation where a wizard (or maybe an eldritch knight) had inspiration and the ability to cast shield, so the DM had to say both what he rolled and what the total was. I suppose in that situation you could revert to saying the total AC you'd hit, rather than needing to also say what the roll was.

[Basch]

Usually I'll let my players know what came up on the die for a creature's attack roll, but won't tell them what the total is with modifiers and such. Nothing quite like rolling a 10 and letting the plate wearer know they were hit. All of a sudden everyone panics and they scramble to get out of melee range. It's some of the most fun I can have, without being forced to cuddle afterwards.

[coredump]

Real life considerations are tricky. In real life, if you see a blow coming you can get out of the way - and if you don't see it you can't do anything about it. How shield is supposed to work in this setting is tricky to understand really. How is it that you see a blow coming and have enough time to cast a spell - but not enough time to get out of the way or block? Maybe that makes sense with a fireball or something but less so with a sword swing.
5E deals with that by assuming you have 360 degree vision. You are looking around so much that you can see anything happening nearby. Its why someone can't just walk up behind you, etc...

[Knaight]

Real life considerations are tricky. In real life, if you see a blow coming you can get out of the way - and if you don't see it you can't do anything about it. How shield is supposed to work in this setting is tricky to understand really. How is it that you see a blow coming and have enough time to cast a spell - but not enough time to get out of the way or block? Maybe that makes sense with a fireball or something but less so with a sword swing.

It totally makes sense with a sword swing. Often it's something to the effect of both of you are in pretty close (so dodging anything is going to be all sorts of tricky), your weapon is out of position, probably complements of some pretty good shield work on the opponent's part, and the sword is incoming with too little time to do anything about it. The shield spell fits in that gap.