D&D 5E Reactions

[Ovinomancer]

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.

There's only a contradiction if you insist on a formalized timing. There is no formalized timing in 5e, just the statements that reactions occur after their triggers unless they say otherwise. Since Uncanny Dodge does not say otherwise, it occurs after the hit is completed. Since shocking grasp prevents reactions on a hit, you cannot react to that hit (except with shield, which specifically says it interrupts it's own trigger and can negate it). There, no timing charts and everything works just fine. It's only when you apply a strict order of events that's absent in the rules that you end up with your contradictions.

 

[Ovinomancer]

...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)

Ding. You can't use UA until the creature leaves your reach, but when you use UA, you get to go back and interrupt the leaving so you attack before they leave. UA triggers after the leaving, but then interrupts the leaving. Simple.

 

[Arial Black]

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.

The rules actually do already have it! We know this because things do work in a certain order, whether or not there is a sentence in the book which formalises it.

UD dodge already works, and the only rule it needs is itself.

UD works by happening between the hit roll being ascertained as a success, and the effects of that hit being applied. That's the rule that exists (in the wording of Uncanny Dodge), and that's the timing. No separate rule needed.

 

[Ovinomancer]

The rules actually do already have it! We know this because things do work in a certain order, whether or not there is a sentence in the book which formalises it.

UD dodge already works, and the only rule it needs is itself.

UD works by happening between the hit roll being ascertained as a success, and the effects of that hit being applied. That's the rule that exists (in the wording of Uncanny Dodge), and that's the timing. No separate rule needed.

UD doesn't say it does this, though. Where are you getting that it happens between the attack being determined it's a successful hit and the effects being applied? More to the point, how can UD halve damage that hasn't happened yet?

 

[Dausuul]

Several people have made the point that D&D doesn't have precise timing rules that could answer this question. They're right. I may like the M:tG stack system, but it doesn't apply here.

So: Throw all that out the window, and let's talk about what's happening in the game world. Normally, when the rogue is subjected to an attack, the rogue can use Uncanny Dodge to halve the damage by doing... what?

Well, we don't know exactly. The ability doesn't have a description. However, whatever the rogue is doing, it's hard to explain how it could be done after the attack physically connects. It makes far more sense to assume the rogue is evading at the last instant, so that a solid blow ends up being a glancing one.

Now, let's look at shocking grasp. What is it doing? Well, it's charging up the caster's hand with electricity, so that touching an enemy results in a nasty zap. The zap causes momentary disorientation, preventing the enemy from reacting for a moment.

So far, so good. What happens when we put the two together? The caster reaches for the rogue to deliver a zap. The rogue tries to evade at the last instant, so the caster will only connect with a finger or two instead of a full-hand grip. Does the disorientation effect prevent the rogue from doing this? Of course not; the zap hasn't happened yet, so the rogue isn't disoriented.

 

[Oofta]

The rules actually do already have it! We know this because things do work in a certain order, whether or not there is a sentence in the book which formalises it.

UD dodge already works, and the only rule it needs is itself.

UD works by happening between the hit roll being ascertained as a success, and the effects of that hit being applied. That's the rule that exists (in the wording of Uncanny Dodge), and that's the timing. No separate rule needed.

Does it?

Uncanny Dodge
Starting at 5th level, when an attacker that you can see
hits you with an attack, you can use your reaction to halve
the attack’s damage against you.

I don't see anything that applies to the current debate. There is no sequence specified anywhere that I know of for applying damage and spell effects. With the case of shocking grasp I would say that the electricity coursing through your body is what causes the damage and shuts down the reaction.

If you get shocked you suffer both effects at the same time.

 

[TheWriterFantastic™]

Does it?

Uncanny Dodge
Starting at 5th level, when an attacker that you can see
hits you with an attack, you can use your reaction to halve
the attack’s damage against you.

I don't see anything that applies to the current debate. There is no sequence specified anywhere that I know of for applying damage and spell effects. With the case of shocking grasp I would say that the electricity coursing through your body is what causes the damage and shuts down the reaction.

If you get shocked you suffer both effects at the same time.

This. The debate goes round and round, examples like this keep popping up in arguments against Uncanny Dodge occurring before the target being robbed of a reaction -- we have examples of reactions being triggered specifically by a hit events, by damage events, by attack events, and by spell casting events, yet the whole picture is ignored -- why would each spell differentiate these things, if these events weren't occurring in separate steps of a sequence?

An attack event encompasses the whole sequence, as does the spell casting event. Spells that trigger specifically off of spell casting typically have language to indicate the spell in question interrupts the casting.

Meanwhile the attack event occurs, and a reaction triggering off of the event may not have language that indicates it occurs prior to the attack event, so logically it occurs afterward.

However, the hit and damage events are different in that they are included in the attack event -- why indicate them individually if they are so intrinsically linked as to be inextricable from each other?

It's because hit and damage are two separate events in the overall sequence of the attack super-event. The reaction keying off of a hit occurs between the hit event and the damage event -- and since logic would also dictate that if the effect event occurs either simultaneously with the damage or subsequent to it, and the reaction doesn't postpone the damage for it to take place after the effect, the reaction that triggers on a hit takes place after the hit, but before the damage and effect.

If the Shocking Grasp unleashes its damage and effect simultaneously, as described in the post above, they would occur after the reaction that occurred after the hit was confirmed.

 

[Jediking]

This is a long thread, and I like (most of) the arguments from both sides, because they give cool explanations and game scenes and make me think. Any DM can make their own call and this is such a cookie-cutter case I doubt any call is the 'wrong one'.

But look at the RAW to argue the RAW. Call it however you want. If you want Rogues to be nimble untouchable tricksters in your game, let UD work. If you want some casters to have a trick to trip them up, let Shocking Grasp take away their reaction.

But by RAW:
"Uncanny Dodge
Starting at 5th level, when an attacker that you can see hits you with an attack, you can use your reaction to halve the attack’s damage against you."
So usually, it would go: On a hit, but BEFORE anything else applies, you can use your reaction to dodge a bit away. Then roll Damage and take half.

"Shocking Grasp:
Make a melee spell attack against the target. You have advantage on the attack roll if the target is wearing armor made of metal. On a hit, the target takes 1d8 lightning damage, and it can’t take reactions until the start of its next turn."
Here, you hit someone with your attack roll, and two things happen. They take 1d8 lightning damage, and lose their reaction.

So the question by RAW is: does SG "and it can’t take reactions until the start of its next turn" apply on the hit (in which case no UD), or at the same time/after as damage (so UD will trigger beforehand).

And there is no set answer to please everyone. Reactions are instant from a trigger. Shocking Grasp's duration is Instant. Both UD and SG's effect trigger on a hit, both are pretty specific, and neither takes absolute precedence. But basically the argument is between these:
1. hit->[reaction: UD]->damage+lose reaction. Here UD would work
2. hit->lose reaction->[reaction lost}->damage. Here UD would not work

Call it how you want, just be consistent. How would this affect a Goliath's Stone Endurance racial trait? Or a Tempest Cleric's Wrath of the Storm feature? Or yes, even the Shield spell?

Personally I'd let Shocking Grasp prevent all of them. That's just me. But it's a DM call, like every other one. I think most cases of Shocking Grasp is to back away without provoking attacks. Giving it more or less uses is a table decision. Look at that thread on Chill Touch and Trolls/Vampires. Phew, that was a fun read too.

 

[Ovinomancer]

Several people have made the point that D&D doesn't have precise timing rules that could answer this question. They're right. I may like the M:tG stack system, but it doesn't apply here.

So: Throw all that out the window, and let's talk about what's happening in the game world. Normally, when the rogue is subjected to an attack, the rogue can use Uncanny Dodge to halve the damage by doing... what?

Well, we don't know exactly. The ability doesn't have a description. However, whatever the rogue is doing, it's hard to explain how it could be done after the attack physically connects. It makes far more sense to assume the rogue is evading at the last instant, so that a solid blow ends up being a glancing one.

Now, let's look at shocking grasp. What is it doing? Well, it's charging up the caster's hand with electricity, so that touching an enemy results in a nasty zap. The zap causes momentary disorientation, preventing the enemy from reacting for a moment.

So far, so good. What happens when we put the two together? The caster reaches for the rogue to deliver a zap. The rogue tries to evade at the last instant, so the caster will only connect with a finger or two instead of a full-hand grip. Does the disorientation effect prevent the rogue from doing this? Of course not; the zap hasn't happened yet, so the rogue isn't disoriented.

There's no reason to say that ID must be a partial dodge only. One of the basic principles in martial arts is how to take a hit, and many of those are reactions after the strike lands to roll with th he impact. You're locking in one description that also results in the answer you like. UD does not have to work as you describe it.

 

[Ovinomancer]

This. The debate goes round and round, examples like this keep popping up in arguments against Uncanny Dodge occurring before the target being robbed of a reaction -- we have examples of reactions being triggered specifically by a hit events, by damage events, by attack events, and by spell casting events, yet the whole picture is ignored -- why would each spell differentiate these things, if these events weren't occurring in separate steps of a sequence?

An attack event encompasses the whole sequence, as does the spell casting event. Spells that trigger specifically off of spell casting typically have language to indicate the spell in question interrupts the casting.

Meanwhile the attack event occurs, and a reaction triggering off of the event may not have language that indicates it occurs prior to the attack event, so logically it occurs afterward.

However, the hit and damage events are different in that they are included in the attack event -- why indicate them individually if they are so intrinsically linked as to be inextricable from each other?

It's because hit and damage are two separate events in the overall sequence of the attack super-event. The reaction keying off of a hit occurs between the hit event and the damage event -- and since logic would also dictate that if the effect event occurs either simultaneously with the damage or subsequent to it, and the reaction doesn't postpone the damage for it to take place after the effect, the reaction that triggers on a hit takes place after the hit, but before the damage and effect.

If the Shocking Grasp unleashes its damage and effect simultaneously, as described in the post above, they would occur after the reaction that occurred after the hit was confirmed.

There's no need to suppose this necessitates a specific framework. Reactions work on triggers, which can be anything. Specific reactions have specific triggers, but that only interesting or informative for that reaction. Nothing about the existence of a trigger infers a broader yet unspoken framework. I'll say that again, you shouldn't infer an intended framework from a specific triggers existence, especially if there's no other reference to that framework.