D&D 5E Point me to the rule please:

[FormerlyHemlock]

The key problem IMO is that Warcasting a spell as an opportunity attack just doesn't make any sense. It leads to ridiculous situations and exploits like "I run by the wizard before hitting the dragon"/"I use my opportunity attack to Haste my buddy as he runs by." Opportunity attacks are already kind of sketchy from a realism standpoint, and converting them into spells just makes the problem worse. Why does running away from a wizard make it easier for him to cast spells on you?

From a game balance perspective, Warcaster is fine, but from a game physics perspective it's incoherent and would be better off rewritten.

 

[ccooke]

The key problem IMO is that Warcasting a spell as an opportunity attack just doesn't make any sense. It leads to ridiculous situations and exploits like "I run by the wizard before hitting the dragon"/"I use my opportunity attack to Haste my buddy as he runs by." Opportunity attacks are already kind of sketchy from a realism standpoint, and converting them into spells just makes the problem worse. Why does running away from a wizard make it easier for him to cast spells on you?

From a game balance perspective, Warcaster is fine, but from a game physics perspective it's incoherent and would be better off rewritten.

... Did you actually read the feat?

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.

I mean, sure, if you want to cast haste on a hostile creature, go ahead... but you absolutely cannot cast the spell on an ally.

 

[FormerlyHemlock]

... Did you actually read the feat?

Yes.

I mean, sure, if you want to cast haste on a hostile creature, go ahead... but you absolutely cannot cast the spell on an ally.

You say that as if the "hostile" requirement makes the game physics more coherent, not less. Your rules-lawyery interpretation just leads to players trying to declare their PCs "hostile" (but willing) to each other temporarily so the spells can be cast. It's not a real restriction, and it doesn't make the ability make any more sense. I didn't elaborate on the "hostile" metagaming in my original post, but that's part of what I was thinking of when I wrote "it leads to."

If Warcaster were rewritten to exclude the "spellcasting as opportunity attack" ability, ridiculous issues would no longer arise from it.

 

[Sage Genesis]

People trying to "trick" reality itself by pretending to be hostile for a split-second... Glad to see we still have our senses of humor.


This is not official but there's a fix to War Caster that's simple, effective, and sticks to the spell's intent: houserule it so that only spells which use attack rolls can be used. So that's Fire Bolt, Shocking Grasp, even Vampiric Touch if you want. But none of this Haste nonsense.

 

[FormerlyHemlock]

People trying to "trick" reality itself by pretending to be hostile for a split-second... Glad to see we still have our senses of humor.


This is not official but there's a fix to War Caster that's simple, effective, and sticks to the spell's intent: houserule it so that only spells which use attack rolls can be used. So that's Fire Bolt, Shocking Grasp, even Vampiric Touch if you want. But none of this Haste nonsense.

Yes, that would be a decent rewrite.

 

[ccooke]

Yes.



You say that as if the "hostile" requirement makes the game physics more coherent, not less. Your rules-lawyery interpretation just leads to players trying to declare their PCs "hostile" (but willing) to each other temporarily so the spells can be cast. It's not a real restriction, and it doesn't make the ability make any more sense. I didn't elaborate on the "hostile" metagaming in my original post, but that's part of what I was thinking of when I wrote "it leads to."

If Warcaster were rewritten to exclude the "spellcasting as opportunity attack" ability, ridiculous issues would no longer arise from it.

Nothing ridiculous can come from the War Caster feat unless you go against the rules of the game. If the DM allows you to metagame when you're hostile, then that is a playstyle that is already against both the spirit and letter of the rules. That's a perfectly reasonable house rule, if your group enjoys it, but it's not something that the designers of the game ought to worry about. The point of the War Caster feat is that you have trained yourself to be able to cast simple one-target spells quickly, to take advantage of an opponent fleeing you. The "physics" problem you describe simply doesn't make sense to me - every PC has trained to take advantage of opportunity attacks. Training as a War Caster extends that training to be able to cast spells that only target the triggering creature; the feat is clear and the implication within world physics is that any spell with more than one target simple takes too much thought to cast as a reaction this way, and trying to cast on a non-hostile target is something that the PC has not trained for.

I would, for instance, think it would be perfectly reasonable to create a feat-level ability that provided a new trigger - say, "An ally is hit within 10' of you" as a pulled-from-the-air example and gave you the ability to use your reaction to cast a one-target spell on them. That seems entirely within the power level of a feat, and quite powerful. The key within the game physics, as you term it, is that the feat would represent the training to react to those events properly.

Just to be clear - if you have fun playing with the ability to declare when you're hostile, that's absolutely fine. The only people who can decide that a playstyle is right or not are the group, of course. However, it is not supportable in any way under the rules. The designers of the game should not have to phrase every single bit of content so that it makes sense when people break the rules that it is based upon.

 

[FormerlyHemlock]

Nothing ridiculous can come from the War Caster feat unless you go against the rules of the game. If the DM allows you to metagame when you're hostile, then that is a playstyle that is already against both the spirit and letter of the rules. That's a perfectly reasonable house rule, if your group enjoys it, but it's not something that the designers of the game ought to worry about. The point of the War Caster feat is that you have trained yourself to be able to cast simple one-target spells quickly, to take advantage of an opponent fleeing you. The "physics" problem you describe simply doesn't make sense to me - every PC has trained to take advantage of opportunity attacks. Training as a War Caster extends that training to be able to cast spells that only target the triggering creature; the feat is clear and the implication within world physics is that any spell with more than one target simple takes too much thought to cast as a reaction this way, and trying to cast on a non-hostile target is something that the PC has not trained for.

Your narrow focus on the letter of the "hostile" law simply converts the ridiculousness into a different form. If "hostile" is significant from a crunch perspective, and single-target spells can only be cast on hostile targets, then Warcaster becomes an infallible spy-detector. Just have everybody try to run past you and cast Ray of Frost on them as they go by. Only the "hostile" creatures will actually be targeted by a spell and all the friendlies will have nothing happen to them.

That's still as ridiculous as Haste, it's just a different kind of ridiculous. The root cause of the ridiculousness is that the feat is modifying the tempo at which spells are cast.

From a game balance perspective, Warcaster is fine, but from a game physics perspective it's incoherent and would be better off rewritten.

 

[Rune]

Furthermore, reactions triggered by opportunity attacks are melee attacks, not spell attacks

Strictly speaking, the phrasing used for opportunity attacks does not preclude spell attacks; it just limits them to melee spell attacks. War Caster expands that to any single target, action-casting time spell.

 

[ccooke]

Your narrow focus on the letter of the "hostile" law simply converts the ridiculousness into a different form. If "hostile" is significant from a crunch perspective, and single-target spells can only be cast on hostile targets, then Warcaster becomes an infallible spy-detector. Just have everybody try to run past you and cast Ray of Frost on them as they go by. Only the "hostile" creatures will actually be targeted by a spell and all the friendlies will have nothing happen to them.

That's still as ridiculous as Haste, it's just a different kind of ridiculous. The root cause of the ridiculousness is that the feat is modifying the tempo at which spells are cast.

From a game balance perspective, Warcaster is fine, but from a game physics perspective it's incoherent and would be better off rewritten.

No, the game doesn't work like a finite state machine. "Hostile" is not a message that appears in flashing neon above the target and it is not denoted by the colour of the circle at their feet. This is a table top RPG, not a computer game, and the key point here is that there is a human DM running the game.

I'm not focussing on the letter of any of these rules. I'm focussing on what makes sense from an in-game perspective - and that means that someone is hostile because my character sees them as a threat. All you are presenting as arguments about this feat being "bad" are "Well, if you metagame it like this and go against the intent and letter of the rules like so, you get a ridiculous result". Yes, you do. Of course you do.

If I decide that "Once per turn" means my rogue can sneak attack on every hit, then I am going to get a ridiculous result according to the rules of the game. If I decide that concentration on some spells doesn't count... ridiculous result. You are focussing on rules lawyering your way to interpretations of the rules that simply don't make sense from the perspective of the written rules or their intent.

As I said, if you and your group enjoy that, more power to you. The game is what you make of it. But you shouldn't blame the game when you get a ridiculous result, if this is what you're doing.

A hostile creature is one your character believes to be hostile. Could one of your party pretend to be hostile? Yes, of course. They could do so by, oh, maybe being hostile? Attacking your PC? That would do it. Could you fool yourself into believing that an ally is hostile? Sure. But if you then abused this rule to cast a spell on them, if I were the DM I would insist that you used something damaging to them.. after all, if you can tell they're not hostile enough to cast Haste on them, then you know they aren't hostile and your training doesn't kick in.

You want to cast Haste on an ally outside of your turn? Ready an action to do it.

 

[FormerlyHemlock]

A hostile creature is one your character believes to be hostile. Could one of your party pretend to be hostile? Yes, of course. They could do so by, oh, maybe being hostile? Attacking your PC? That would do it. Could you fool yourself into believing that an ally is hostile? Sure. But if you then abused this rule to cast a spell on them, if I were the DM I would insist that you used something damaging to them.. after all, if you can tell they're not hostile enough to cast Haste on them, then you know they aren't hostile and your training doesn't kick in.

So in your game, you'd want the PCs to be insulting and/or stabbing each other in order to gain combat advantage against their enemies. Yeah... no. If you can't see how ridiculous that is, I can't help you. Better IMO to just rewrite Warcaster. The suggestion up-thread that it "lets you substitute a spell with an attack roll for an opportunity attack" would be reasonably straightforward.

Incidentally, Haste would be an awesome spell to cast on enemies, if you could find an enemy willing to have you cast it on him (due to trickery or whatever). Auto-stunlock for one round, no save, as soon as you end it, which you will do at the worst possible time.