Can you attempt an impossible attack?

[sayaijin]

I was working on some homebrew material that would allow a player to use a resource to still get some damage (but not the full attack's worth) in even if they miss an attack.

One thing I want to look into first though is whether or not a player can attempt an impossible attack?

If so, then my homebrew would allow players to still get some damage in when trying to stab from 300ft away. If that's the case then my content may require some more tuning.

[MoiMagnus]

No. Every attack that you are allowed to attempt is successful if you roll a natural 20 on your d20.
Since any attack you attempt will succeed with at least 5% chance by the rules, if follows that you cannot attempt an attack that is truly impossible.

However, blind attacks (where you don't really know the position of the target, but with enough luck will hit) are totally possible. You might want to add to your homebrew that it doesn't work with disadventaged attacks if you want to remove those usages.

[Unoriginal]

I was working on some homebrew material that would allow a player to use a resource to still get some damage (but not the full attack's worth) in even if they miss an attack.

One thing I want to look into first though is whether or not a player can attempt an impossible attack?

If so, then my homebrew would allow players to still get some damage in when trying to stab from 300ft away. If that's the case then my content may require some more tuning.

Define "attempt" and "impossible", please.


Trying to stab someone through prison bar when said someone is out of range, for example, makes it impossible for you to damage them (unless special circumstances like a magic sword or being on a plane where hostile intent is enough to hurt someone). But it could still be described as "an attempt", depending on your definition. In either case an attack roll wouldn't be called for.

But in all cases, missing with an attack you could possibly succeed and failing to do an impossible attack isn't the same. As MoiMagnus notes, if you roll for an attack there's always 5% chances you hit, outside of advantage/disadvantage.

[sayaijin]

Gotcha. Yeah that's the ruling I assumed based on other skill checks (you wouldn't let your players jump to the moon or convince a king to give up his throne on a Nat 20).

I also see the rules for total cover say you can't even target the creature for an attack, but I just wanted to make sure.

[MoiMagnus]

Yeah that's the ruling I assumed based on other skill checks (you wouldn't let your players jump to the moon or convince a king to give up his throne on a Nat 20).

Attack rolls are not technically skill checks.

There are 3 kind of checks: attacks rolls, ability/skill checks, and saving throws. While they have very similar rules, rules and bonuses to one don't always affect the others. And in particular, the rule for Nat 20 being an automatic success only exists for attack rolls.

[stoutstien]

Attack rolls are not technically skill checks.

There are 3 kind of checks: attacks rolls, ability/skill checks, and saving throws. While they have very similar rules, rules and bonuses to one don't always affect the others. And in particular, the rule for Nat 20 being an automatic success only exists for attack rolls.

And the odd man out with a nat 20 on a death saving throw bringing you to 1 hp.

[sayaijin]

So the mechanical wording of my homebrew is for a rogue subclass:

"If you make a weapon attack and do not deal your sneak attack damage, you can [spend resource]. If you do, then you deal force damage equal to your sneak attack to the target."

There's fluff, but that's the crunch.

[sayaijin]

So the intention was two-fold: they can use non-finesse weapons and they can guarantee at least their sneak attack damage even if they miss.

I just wanted to make sure they couldn't spam it against someone out of range or behind cover.

Thanks!

[DwarfFighter]

One thing I want to look into first though is whether or not a player can attempt an impossible attack?

By the rules, no. You cannot attack targets you cannot reach with your 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.
(...)


Sitting at the inn and stabbing at air isn't going to kill the king in his castle. You need to get closer.

Also your attack needs to be able to reach the target: Stabbing at an enemy on the other side of a solid stone wall is going to fail due to Total Cover. You need to find some way through to have any chance.

You can attempt to attack things you cannot see:


When you attack a target that you can't see, you have disadvantage on the attack roll. This is true whether you're guessing the target's location or you're targeting a creature you can hear but not see. If the target isn't in the location you targeted, you automatically miss, but the DM typically just says that the attack missed, not whether you guessed the target's location correctly.

Targeting an unoccupied square makes it impossible for the attack to score a hit - there isn't anything there to hit! However, here I feel there is some room for the GM to allow some improvisation. If you are shooting an arrow trying to hit an unseen enemy, then surely the arrow's trajectory will pass through more squares than just the selected location! And swinging a sword wildly through a couple of adjacent squares should be possible too.

Other than that... Well, this version of DnD doesn't seem to care to make it too difficult to score a hit. Have a look at the AC of various NPCs and monsters, and you'll find most are in the range of 12-18. The conditions that make NPCs harder to hit than their AC would suggest are generally cover and disadvantage, and there are ways to get around those.

I don't think impossible attacks are a thing you need to worry about.

-DF

[sayaijin]

Define "attempt" and "impossible", please.


Just for clarification, I meant can a player make an attack at a character behind total cover or out of range. They wouldn't even roll because it's an auto fail. I realize now that you can't attack without an attack roll.

[Tanarii]

Just for clarification, I meant can a player make an attack at a character behind total cover or out of range. They wouldn't even roll because it's an auto fail. I realize now that you can't attack without an attack roll.
Yes you can make an attack with a weapon on a creature with total cover, provided it is with reach (melee) or range (ranged).Your house rule would be triggered by that.

You can't cast a spell on it though, unless it says otherwise.

[sayaijin]

Yes you can make an attack with a weapon on a creature with total cover, provided it is with reach (melee) or range (ranged).Your house rule would be triggered by that.

You can't cast a spell on it though, unless it says otherwise.

"A target with total cover can't be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle."

[Tanarii]

"A target with total cover can't be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. A target has total cover if it is completely concealed by an obstacle."
Huh. I stand corrected. I could have sworn that was a known issue with targeting in 5e.

I've played too many editions of D&D, and occasionally I get them mixed up. "Roll a Save vs a poison or die ... uh, I mean Con save for 1d6 damage."

[sayaijin]

Huh. I stand corrected. I could have sworn that was a known issue with targeting in 5e.

I've played too many editions of D&D, and occasionally I get them mixed up. "Roll a Save vs a poison or die ... uh, I mean Con save for 1d6 damage."

I feel like I kinda want people to be able to attempt an attack they know will fail (without an attack roll) just so they could use my homebrew subclass feature, but I recognize now that it's not RAW.

[Danielqueue1]

So the mechanical wording of my homebrew is for a rogue subclass:

"If you make a weapon attack and do not deal your sneak attack damage, you can [spend resource]. If you do, then you deal force damage equal to your sneak attack to the target."

There's fluff, but that's the crunch.

Warning! Dual wielding rogues would be able to take the attack action, hit, deal sneak attack damage, then bonus action off-hand attack, and then use that resource to deal sneak attack damage again. Make sure you want to let people sneak attack twice in one turn, (three times in a round with reactions) if you go with this wording.

[Dalinar]

^How do y'all feel about this wording? "You can use a bonus action to [spend resource] and do force damage equal to your Sneak Attack damage to a target you can see within X feet [maybe range of a weapon you are holding?]. You cannot use this feature on the same turn you deal Sneak Attack damage through any other means."

I'm not sure that matches the fluff you want, but it covers "attack the target and miss" as well as "attack the target and not deal Sneak Attack damage (due to being ineligible or whatever)" and "do something else with my action this turn but still do my Sneak Attack damage." It costs a bonus action, however--just sounds better-balanced to me that way off the cuff, but maybe you have "no action required" or some other condition you're looking for.

Sound like what you want?

[Herbert_W]

5e has some pretty crazy implications by RAW when players target enemies that can't be seen, where the player doesn't know whether or not they are in range or behind total cover. These are normally glossed over in play.

While your homebrew ability doesn't poke any new holes, it does drive a wedge into this existing one. Here's the hole by itself:


Player: Can I attack the invisible goblin with my dagger when I'm standing here?

DM: If you can guess where it is, you can attack with disadvantage.

Player: So, that means it must be within reach and can't be behind total cover relative to my location. I move over here. Now, can I attack the goblin from this location?

DM: Wait, what? What are you trying to do?

Player: A creature that's out of range or in total cover can't be targeted by an attack. If I'm able to attack it from a given location, that narrows down where it could be. By attempting attacks from different locations and seeing if you let us roll, we can triangulate it's location.

DM: There's no way that could work.

Player: By RAW, it does.

DM: Let me check . . . OK, you're right, but that's obviously crazy and not RAI. I'm just going to let you roll, whether you can actually make the attack or not.

Player: OK, I roll to attack.

DM: You miss. I'm not going to tell you whether you missed because you guessed the wrong location, or you just missed.


That's all well and good. There's a hole in RAW, but there's an obvious patch that follows RAI: always let players roll to attack, even if the attack can't (unbeknownst to them) actually be made.

Now let's see what happens when we add your homebrew, as currently written.


Player: Dangit. Can I use sayaijin's homebrew ability?

DM: You can roll for damage. The goblin will take damage if it was in range.

Player: This is an ability that expends a resource when used. If the target is out of range, the ability can't be used and the resource won't be expended. I need to know whether I should mark that resource as spent or not.

DM: Telling you that would also tell you whether to goblin was in range or not when you attacked - which is something that you shouldn't be able to find out this way.

Player: So . . . I don't know how many uses of this ability I have left, then?

DM: You're right, that doesn't make sense. We could, uh . . . what do you think would be a realistic solution?

Player: Realistically, if I damage a goblin with my dagger, I will feel it. So using this ability should tell me whether the goblin was in range or not.

DM: OK.

Player: If we're going for realism, then I should also be able to feel where the goblin is. After all, I just damaged it with a melee weapon.

DM: OK. The goblin is here. Roll for damage.


Your ability has, unexpectedly, become more powerful. It's not ridiculous yet though. Yet.


DM: So, that goblin is dead.

Player: There's a pixie controlling them, right? It's likely to be within range. I throw my dagger at it.

DM: You can't see a pixie anywhere. You're right that it's certainly very close, but you don't know exactly where.

Player: I'm throwing my dagger anyways. I guess that the pixie is way out here, where I can't see because of the fog.

DM: You miss. Obviously.

Player: I expected that. I use sayaijin's homebrew ability.

DM: But you missed completely! The pixie isn't even there!

Player: If it's within range, by RAW, the ability still works.

DM: OK, so the ability works. If the pixie is within range. Which, to be clear, you don't know.

Player: Should I mark off a use of sayaijin's homebrew resource?

DM: Oh hell.



What our hypothetical DM should do, and what I think that you should do, is limit the ability to targets that are visible and within a certain range (say 30 ft, or within reach of the player's melee weapon). You should also think about how you want this ability to interact with the mirror image spell. By your current wording the sneak attack would be guaranteed damage against the real target, which is circumstantial and a reasonable enough benefit that it's probably fine; it's just freakishly counterintuitive.

Otherwise this is, circumstantially, a very nutty ability.

[MoiMagnus]

5e has some pretty crazy implications by RAW when players target enemies that can't be seen, where the player doesn't know whether or not they are in range or behind total cover. These are normally glossed over in play.

If one wants to take a somewhat realistic approach to targetting invisible enemies, you would need to make a difference between
(1) Missing the target entirely (obtaining less than 10+Dex, or targeting the wront spot)
(2) Hitting the armour/shield without harming the target (between 10+Dex and the actual AC)
(3) Actually hitting the target

[sayaijin]

Warning! Dual wielding rogues would be able to take the attack action, hit, deal sneak attack damage, then bonus action off-hand attack, and then use that resource to deal sneak attack damage again. Make sure you want to let people sneak attack twice in one turn, (three times in a round with reactions) if you go with this wording.


Thank you for reminding me. I just need to add "this uses your sneak attack for the turn"

[sayaijin]

5e has some pretty crazy implications by RAW when players target enemies that can't be seen, where the player doesn't know whether or not they are in range or behind total cover. These are normally glossed over in play.

While your homebrew ability doesn't poke any new holes, it does drive a wedge into this existing one. Here's the hole by itself:


Player: Can I attack the invisible goblin with my dagger when I'm standing here?

DM: If you can guess where it is, you can attack with disadvantage.

Player: So, that means it must be within reach and can't be behind total cover relative to my location. I move over here. Now, can I attack the goblin from this location?

DM: Wait, what? What are you trying to do?

Player: A creature that's out of range or in total cover can't be targeted by an attack. If I'm able to attack it from a given location, that narrows down where it could be. By attempting attacks from different locations and seeing if you let us roll, we can triangulate it's location.

DM: There's no way that could work.

Player: By RAW, it does.

DM: Let me check . . . OK, you're right, but that's obviously crazy and not RAI. I'm just going to let you roll, whether you can actually make the attack or not.

Player: OK, I roll to attack.

DM: You miss. I'm not going to tell you whether you missed because you guessed the wrong location, or you just missed.


That's all well and good. There's a hole in RAW, but there's an obvious patch that follows RAI: always let players roll to attack, even if the attack can't (unbeknownst to them) actually be made.

Now let's see what happens when we add your homebrew, as currently written.


Player: Dangit. Can I use sayaijin's homebrew ability?

DM: You can roll for damage. The goblin will take damage if it was in range.

Player: This is an ability that expends a resource when used. If the target is out of range, the ability can't be used and the resource won't be expended. I need to know whether I should mark that resource as spent or not.

DM: Telling you that would also tell you whether to goblin was in range or not when you attacked - which is something that you shouldn't be able to find out this way.

Player: So . . . I don't know how many uses of this ability I have left, then?

DM: You're right, that doesn't make sense. We could, uh . . . what do you think would be a realistic solution?

Player: Realistically, if I damage a goblin with my dagger, I will feel it. So using this ability should tell me whether the goblin was in range or not.

DM: OK.

Player: If we're going for realism, then I should also be able to feel where the goblin is. After all, I just damaged it with a melee weapon.

DM: OK. The goblin is here. Roll for damage.


Your ability has, unexpectedly, become more powerful. It's not ridiculous yet though. Yet.


DM: So, that goblin is dead.

Player: There's a pixie controlling them, right? It's likely to be within range. I throw my dagger at it.

DM: You can't see a pixie anywhere. You're right that it's certainly very close, but you don't know exactly where.

Player: I'm throwing my dagger anyways. I guess that the pixie is way out here, where I can't see because of the fog.

DM: You miss. Obviously.

Player: I expected that. I use sayaijin's homebrew ability.

DM: But you missed completely! The pixie isn't even there!

Player: If it's within range, by RAW, the ability still works.

DM: OK, so the ability works. If the pixie is within range. Which, to be clear, you don't know.

Player: Should I mark off a use of sayaijin's homebrew resource?

DM: Oh hell.



What our hypothetical DM should do, and what I think that you should do, is limit the ability to targets that are visible and within a certain range (say 30 ft, or within reach of the player's melee weapon). You should also think about how you want this ability to interact with the mirror image spell. By your current wording the sneak attack would be guaranteed damage against the real target, which is circumstantial and a reasonable enough benefit that it's probably fine; it's just freakishly counterintuitive.

Otherwise this is, circumstantially, a very nutty ability.

I agree that I should limit it to enemies that the player sees. I'll have to think about illusions.