D&D 5E Reactions

[seebs]

For most purposes, it doesn't matter whether uncanny dodge happens before or after the hit.

But here's a thought experiment for you: You have five hit points. You are hit for 8 points of damage. The attack would, in general, qualify for Uncanny Dodge.

Can you use Uncanny Dodge to halve the damage? If you can, then the uncanny dodge reaction is being activated prior to the damage happening.

I would argue that "when an attacker that you can see hits you" specifies the trigger to be "hit". Not "damage". So I'd have Uncanny Dodge fire off once you know you've been hit, but before damage is rolled. That's another interesting question; do you get to wait until damage is rolled before using uncanny dodge, or do you have to decide in advance?

I'd say that, if you have to decide in advance, then the damage-halving works and after that you lose the ability to take reactions for a while. If you get to wait to see damage before deciding, it's less obvious.

 

[Uller]

Either way, a cantrip was just used to cause the target to not be able to take reactions until it's next turn. Unless the target is very low on HP and you are very desperate to take it to 0 hp, the reason you are using Shocking Grasp is to achieve that state (so someone can do something that depends on the target NOT taking a reaction)...maybe you want to withdraw without taking an OA, maybe an ally is about to hit the rogue with a much bigger attack and you don't want him to use UD on that....

But yeah, I think the general order of things is trigger happens, reaction happens, reaction effects are applied, trigger effects are applied. Nothing about shocking grasp says that order is modified. So UD should be allowed to halve the damage.

 

[steeldragons]

But yeah, I think the general order of things is trigger happens, reaction happens, reaction effects are applied, trigger effects are applied. Nothing about shocking grasp says that order is modified. So UD should be allowed to halve the damage.

<bolded mine>

You mean except the explicit line in the description of the spell that states, immediately after "On a hit, the target takes d8 lightning damage," that the reaction does not, in fact, happen, "...and it can't take reactions until the end of its next turn."?

Aside from that, you are correct, "Nothing about shocking grasp says that order is modified."

This alleged "order things happen in all cases" is disrupted right at step number two "reaction happens"...because, wait...no it doesn't... Because "trigger happens" first (shocking grasp hit you) and the trigger states, for this particular spell/attack with this particular cantrip, you are just not going to get your reaction [until the end of your next turn].

Specific [shocking grasp description directly addressing this] overrules the generic [how reactions, usually/generally, work].

 

[Croesus]

I agreed, this comes across as a solid interpretation, but the description of Uncanny Dodge is pretty clear: "...when an attacher that you can see hits you with an attack..."

Uncanny Dodge doesn't kick in until you're hit, and Shocking Grasp prevents all reactions once you've been hit. Getting hit triggers Shocking Grasps special effect, which prevents Uncanny Dodge from being used.

Since Uncanny Dodge obviously occurs after you know the attack roll was successful, but prior to rolling any damage, I suspect "hits you with an attack" is shorthand for "rolled successfully to hit you with an attack". If so, then the reaction would occur prior to the effects of Shocking Grasp. YMMV.

 

[The Grassy Gnoll]

Uncanny dodge is, as I see it, reflexes so fast that an otherwise terrible wound is deflected and the damage modified.

So, roll to hit - success triggers the reaction. Damage limited. Other effects, not.

The attacker maybe doesn't get all five digits on the rogue and some of the electricity arcs away. But there is electricity pumped into him; and so he loses his Reaction for his next turn.

I see it as:
Roll to hit
If hit, declare Reaction (in this case, UD)
Roll damage
Modify damage from reaction
Other effects of the attack

In the same way, if it was a poisoned dagger attack, the wound itself would be less grave but the poison would still have been delivered into the rogue's system.

 

[Saeviomagy]

<bolded mine>

You mean except the explicit line in the description of the spell that states, immediately after "On a hit, the target takes d8 lightning damage," that the reaction does not, in fact, happen, "...and it can't take reactions until the end of its next turn."?

Aside from that, you are correct, "Nothing about shocking grasp says that order is modified."

This alleged "order things happen in all cases" is disrupted right at step number two "reaction happens"...because, wait...no it doesn't... Because "trigger happens" first (shocking grasp hit you) and the trigger states, for this particular spell/attack with this particular cantrip, you are just not going to get your reaction [until the end of your next turn].

Specific [shocking grasp description directly addressing this] overrules the generic [how reactions, usually/generally, work].

If you are unconscious, you cannot take actions.

Therefore would you rule that you cannot use uncanny dodge to halve the damage of an attack that would otherwise cause you to fall unconscious?

Would you rule that you cannot cast shield to raise your AC vs an attack that would knock you out if it hit?

 

[steeldragons]

If you are unconscious, you cannot take actions.

Therefore would you rule that you cannot use uncanny dodge to halve the damage of an attack that would otherwise cause you to fall unconscious?

If that attack is a Shocking Grasp, it seems clearly, yes. What any other attack does is of no relevance here. The spell description specifically addresses this scenario.

Would you rule that you cannot cast shield to raise your AC vs an attack that would knock you out if it hit?

Same answer. If that attack is shocking Grasp, which is the thread/question, then no. You can't. If it's anything else (which, from what I have seen/can tell, no other attack negates reactions) then fine, Shield goes off as a reaction, as it is supposed to.

 

[jaelis]

Shocking grasp says you can't take reactions, but so does being unconscious. Why do you judge the effects differently?

 

[steeldragons]

If you're unconscious you're not doing any actions. Reactions would be taking effect, theoretically, before you are unconscious. The fact you can't take reactions while unconscious is...well, kinda just common sense.

As to, "Why judge the effects differently?"

"Because they are different effects," seems like more than sufficient justification.

 

[jaelis]

Well if you want to just say, "that's how I think the spell should work," I'm fine with that. But if you're trying to rules lawyer it, then it seems like the same logic would apply to being knocked unconscious or just taking damage period.