D&D 5E Reactions

[Uchawi]

Uncanny dodge halves the damage and then the spell effect of can't use a reaction kicks in. But 5E is really basic and suffers when it comes to order of precedence for actions, or action economy. At that point it is up to the table.

 

[Oofta]

I think a large part of it is people assuming the only reaction which interrupts is "an interrupt" in M:tG terms. Any reaction which breaks the normal flow of an act interrupts (by the dictionary definition), be that act attack, movement, or urinating and falling into a fetal position. That is what that section of the DMG is about: whether or not a reaction interrupts is a function of its timing, not of an explicit "interrupt" aspect or effect of the reaction.



Right. If the normal flow of the attack is this:
declare attack > roll to hit > check for attack success > roll damage > apply damage and other effects > check for unconsciousness

I think part of the issue is that people always assume it's always Step 1 then Step 2 and then Step 3 followed by Step 4. The rules don't say or indicate that. You declare attack > roll to hit > check for attack success > apply effects and damage (same step) > check for unconsciousness. There's nothing that says effects happen before damage or vice versa.

But yes, as ProphetSword says, the game doesn't need page upon page of minor rules tweaks and clarifications. I'll play this situation, should it ever come up, however my DM says.

Since the rules don't specify, I agree that there is no one true answer. Flip a coin, roll a die, always rule in favor of the PC or whatever method you want to use but some things in 5E are just left up to the DM to work out with his players.

 

[Ovinomancer]

I think a large part of it is people assuming the only reaction which interrupts is "an interrupt" in M:tG terms. Any reaction which breaks the normal flow of an act interrupts (by the dictionary definition), be that act attack, movement, or urinating and falling into a fetal position. That is what that section of the DMG is about: whether or not a reaction interrupts is a function of its timing, not of an explicit "interrupt" aspect or effect of the reaction.



Right. If the normal flow of the attack is this:
declare attack > roll to hit > check for attack success > roll damage > apply damage and other effects > check for unconsciousness

Then uncanny dodge changes it to this:
declare attack > roll to hit > check for attack success | interruption if attack is successful: halve incoming damage | > roll damage > apply damage and other effects > check for unconsciousness

What procproc is saying--and I agree--is that whether the condition which would prevent uncanny dodge is blindness, unconsciousness, or shocking grasp's effect, it is applied after the reaction has been triggered and taken effect.

What you and others have been implying (and please correct me if I'm wrong) is a flow that looks more like this:
declare attack > roll to hit > check for attack success > apply other effects > roll damage > apply damage

where
declare attack > roll to hit > check for attack success | uncanny dodge is triggered here | > apply other effects > roll damage | but doesn't occur until here, if it can | > apply damage

The division of the effects of an attack such that some are applied ahead of others is not supported by the rules, and the idea that a reaction can be triggered but then not occur if it is retroactively made unusable is similarly unsupported. Both are counter-intuitive complications introduced to make this particular interaction work the way it seems you think it should. Jeremy Crawford's ruling, as I see it, is a stealth erratum which changes the trigger of uncanny dodge to "when you take damage from an attack."

But yes, as ProphetSword says, the game doesn't need page upon page of minor rules tweaks and clarifications. I'll play this situation, should it ever come up, however my DM says.

That's a lotta words trying to guess my argument, especially when I've already said that 5e doesn't have such granular timing issues. To put it in your answer, it's:

Normal: Make an attack --> If a hit, apply effects.
Uncanny Dodge: Make an attack --> If a hit, apply effects --> Uncanny dodge triggers off the hit and halves damage effects
UD vs shocking grasp: Make a shocking grasp attack --> if a hit, apply lightning damage and prevent reactions --> no UD because: can't react.

If Uncanny Dodge was triggered by taking damage, it the normal path would fully complete, with full damage being applied to the character and checks made (such as 'am I at zero?' or 'did I just die due to massive damage?') and then UD would fire. Because reactions occur after their triggers resolve unless they have wording otherwise. UD halves damage from an attack, so after the attack and damage is determined, UD fires and interrupts the damage application to halve it. Since the full effects are already there, shocking grasp would prevent UD. It would not prevent shield, because shield interrupts the attack, not the damage like UD does.

 

[Ovinomancer]

I think you are wrong there.

The answer is "When a hostile creature that you can see attempts to move out of your reach."

The attack occurs right before the creatures leaves your reach. The result of the attack might mean the creature is prevented from actually moving out of your reach (perhaps it is dead, perhaps you had Sentinel feat).

No, the answer is in the rules -- when a hostile creature that you can see moves out of your reach." It's a clear sentence that doesn't brook much question as to when a UA fires. It's not 'attempts to move' it's 'moves'.

 

[Arial Black]

But, by the rules, reactions occur after their trigger, yet you're insisting that UD occurs before it's trigger. I'm not following your argument. Is there something I'm missing?

Yes.

Reactions happen after their trigger, unless otherwise specified. UD doesn't specify any special timing, therefore it occurs after its trigger.

But the trigger is not 'being affected by an attack'! The trigger is 'being hit by an attack.

First, attacks are rolled. Then, the effects of being hit are applied (if the attack succeeded), which is usually damage.

Reaction-denial is an effect of the spell, which is only applied after the hit is resolved.

UD is triggered by the hit, not by the effects being applied. UD works before the effects are applied, and therefore before reaction-denial takes effect.

 

[Ovinomancer]

Yes.

Reactions happen after their trigger, unless otherwise specified. UD doesn't specify any special timing, therefore it occurs after its trigger.

But the trigger is not 'being affected by an attack'! The trigger is 'being hit by an attack.

First, attacks are rolled. Then, the effects of being hit are applied (if the attack succeeded), which is usually damage.

Reaction-denial is an effect of the spell, which is only applied after the hit is resolved.

UD is triggered by the hit, not by the effects being applied. UD works before the effects are applied, and therefore before reaction-denial takes effect.

Sorry, the timing your insisting on doesn't exist. It's not in the rules. You can add it, if it helps your game, but the rules just don't have it.

 

[Valador]

The way I see it, as I've said before, UD takes place after the attack roll but before the attack damage. I'm by no means a genius so I try to rely on what seems to me like common sense understanding.

Key word in Uncanny Dodge is dodge... You cannot "dodge" a hit after the damage is already inflicted, it makes no sense. You cannot magically heal yourself by dodging after you receive damage... You attempt to dodge an incoming attack that's otherwise going to hit you, therefore the order as intended would most likely be attack roll hits, you attempt to dodge the bulk of the damage, roll for damage.

After14 pages some seem to think that if you play dodgeball and get hit with the ball that if you roll around after being hit by the ball that your post-hit dodging will somehow magically put you back in the game...

Rulings not rules will never work as long as people need everything spelled out for them.

 

[Ovinomancer]

The way I see it, as I've said before, UD takes place after the attack roll but before the attack damage. I'm by no means a genius so I try to rely on what seems to me like common sense understanding.

Key word in Uncanny Dodge is dodge... You cannot "dodge" a hit after the damage is already inflicted, it makes no sense. You cannot magically heal yourself by dodging after you receive damage... You attempt to dodge an incoming attack that's otherwise going to hit you, therefore the order as intended would most likely be attack roll hits, you attempt to dodge the bulk of the damage, roll for damage.

After14 pages some seem to think that if you play dodgeball and get hit with the ball that if you roll around after being hit by the ball that your post-hit dodging will somehow magically put you back in the game...

Rulings not rules will never work as long as people need everything spelled out for them.

And that's fair, but there's nothing important about Uncanny Dodge's name rule-wise. It's a holdover term from previous editions, that's all. It's function is spelled out in it's rules, not it's name. D&D's gonna get very confusing if you take the names of things as unwritten rules.

 

[Cognomen's Cassowary]

That's a lotta words trying to guess my argument, especially when I've already said that 5e doesn't have such granular timing issues. To put it in your answer, it's:

Normal: Make an attack --> If a hit, apply effects.
Uncanny Dodge: Make an attack --> If a hit, apply effects --> Uncanny dodge triggers off the hit and halves damage effects
UD vs shocking grasp: Make a shocking grasp attack --> if a hit, apply lightning damage and prevent reactions --> no UD because: can't react.

If Uncanny Dodge was triggered by taking damage, it the normal path would fully complete, with full damage being applied to the character and checks made (such as 'am I at zero?' or 'did I just die due to massive damage?') and then UD would fire. Because reactions occur after their triggers resolve unless they have wording otherwise. UD halves damage from an attack, so after the attack and damage is determined, UD fires and interrupts the damage application to halve it. Since the full effects are already there, shocking grasp would prevent UD. It would not prevent shield, because shield interrupts the attack, not the damage like UD does.

So you claim that there's no granular timing and then go on to talk about granular timing. Uncanny dodge triggers sometime after "the attack and damage is determined" but before "the damage application." Generously reading "the attack and damage is determined" as synonymous with "If a hit, apply effects," I'll go ahead and add the other to the timeline.

Uncanny Dodge: Make an attack --> If a hit, apply effects --> Uncanny dodge triggers off the hit and halves damage effects --> "the damage application"

And we're back to separating the application of other effects from the application of damage, and then this contradiction:

UD vs shocking grasp: Make a shocking grasp attack --> if a hit, apply lightning damage and prevent reactions --> no UD because: can't react --> "the damage application"

The problem with saying that there is no granular timing is that there is inescapably a sequence of events, no matter how implicit, to make the action of the game comprehensible. The phrasing "On a hit, you roll damage" makes it clear that the check for attack success happens before the roll for damage and the application of effects* ("Basic Rules" 73). The triggers of reactions actually discern between these different stages in the sequence of the attack. Uncanny dodge could easily trigger "when you take damage" and still reduce that damage. How do I know? Absorb elements is a reaction that does exactly that. But uncanny dodge's trigger is something else, "when you are hit." Note that there are also reactions triggered by distinct actions, such as casting a spell in the case of mage slayer or attacking your ally in the case of sentinel, and these occur after the trigger, which is in these cases the full action and not some stage within it.

*I would go so far as to say that in every case "On a hit" is a conditional for gameplay sequencing, essentially shorthand for "If the attack succeeds, then Y," but not an assertion of in-narrative simultaneity. "When you are hit" is used in such cases, where the "you" is clearly not the player but the player character.

 

[Uller]

...clearly the OA cannot happen until a creature attempts to leave your reach, and equally clearly it must happen before the creature actually does leave your reach....

...I am not a great fool, so I can clearly not choose the wine in front of you. But you must have known I was not a great fool, you would have counted on it, so I can clearly not choose the wine in front of me...

...sorry...couldn't resist....(and the correct answer is both)