D&D 5E Reactions

[AaronOfBarbaria]

Overall, I am inclined to allow Shocking Grasp to prevent Uncanny Dodge simply because it makes the spell more interesting. RAF > RAW/RAI at my table.

I agree with the sentiment behind this statement.

In fact, it is why I hadn't bothered making any attempt at sorting out which of these two elements has priority over the other (to borrow fighting game terminology) - because my decision on such a ruling will come down to what seems most appropriate at the moment should this entirely unlikely situation come up at my table.

My choice at that time, should it ever come, will likely be along the lines of "Monsters lose ties to PCs" - whichever game element is the one the player is invoking being the one that "wins" their conflict.

I just don't imagine there will be a time when a monster/npc I'm running has Uncanny Dodge, and I'm certain there will not be a time when a monster/npc has spells but has exhausted all of them more useful than cantrips but is still trying to fight rather than flee or negotiate surrender.

 

[Arial Black]

Fortunately, Jeremy Crawford seems to have answered your follow-up tweet:

"Uncanny Dodge reduces damage before you apply the effects of the damage."

Makes good sense.

Since both damage AND reaction-denial are a consequence of being hit, they must happen at the same time. Therefore, if your Uncanny Dodge represents re-playing the resolution so you never got hit so hard as it initially seemed, by dodging in the first place (as opposed to being damaged and then healing half of that damage) then the damage is not actually applied (removed from your HP total) until AFTER Uncanny Dodge has happened. Since the spell damages AND takes away your ability to use reactions, both damage AND reaction denial happen AFTER Uncanny Dodge.

 

[Arial Black]

For the same reason, I wouldn't allow shield to be used as a reaction, either, mostly because it has paradoxical results if the shield doesn't prevent the shocking grasp from hitting -- at that point, you've reacted to something that forbids your reaction.

There is a difference between a player rolling a 'hit' and the character actually being struck. One is merely a game mechanic (upon which other game mechanics may depend) and the other happens to a creature in-game.

The shield spell, and the game mechanics involved, doesn't represent the creature being hit in-game and then casting shield and them time rewinding in-game. It represents the fact that the creature would have been hit if he hadn't interposed a magical shield of force in the nick of time, preventing the creature ever being hit at all in-game!

The 'hit' mechanic really represents that the creature will be hit, unless the creature can do something about it! Most of the time it can't, and then the creature is actually hit in-game and the effects of the hit are applied. However, some of the time, the creature can do something about it (shield, Uncanny Dodge, Relentless Rage, etc.) and this means that the creature was never affected by what the hit would have been and is instead affected by the attacking effect modified by the reaction. The game mechanic of a 'hit' triggers the reaction, and the effects of being hit (damage, reaction-denial, whatever) are only applied after the reaction.

We know that Uncanny Dodge must work that way. You say that reaction-denial is an effect of being hit, but so is being damaged! But the effects of being hit are only actually applied to the target after Uncanny Dodge has already modified it, and those effects include BOTH damage AND reaction-denial. If those effects were actually applied before the reaction modifies it then it would be Uncanny Healing, and we know that it doesn't work that way.

 

[Valador]

IMO Uncanny Dodge applies before the Shocking Grasp affect takes hold.

My visual interpretation... An electrically charged hand (SG) is about to touch you, you attempt to avoid being hit in a critical area (UD). The attack still manages to hit you but you don't take the full damage because you managed to dodge the brunt of it. So instead of taking a shocking attack to the chest you manage to be grazed on the arm or something. You take less damage and then at the end when the damage is rolled you suffer the reaction nullifying affects of Shocking Grasp.

IMO UD happens in between the attack roll and the damage roll. You know you're going to be hit and you can't stop that from happening, but you can attempt to less the impact by adjusting yourself and dodging somewhat.

 

[Guest 6801328]

Really its an argument about 1/2 or full shocking grasp damage.

That's what I thought before somebody mentioned Mage Slayer. That's the difference between a full Sneak Attack and not.

 

[Uller]

"Monsters lose ties to PCs"

This is my general rule of thumb. Think about shocking grasp and something more meaningful like hellish rebuke. I probably would not allow a moster to use a cantrip to supress the walock player's kewl spell. But if a PC is facing a monster with a similar ability and cleverly comes up with using shocking grasp I'll likely allow it.

But that's because my players are not the rules lawyer sort or the optimizer sort. So thwy wont take that ruling and use it against another ruling later. As a DM I consider it one of my jobs to make sure the players get some opportunity to use the fun stuff their PCs can do and I try to avoid seeming to pull stuff out of the ether that denies them that.

 

[Icharbezol]

This is my general rule of thumb. Think about shocking grasp and something more meaningful like hellish rebuke. I probably would not allow a moster to use a cantrip to supress the walock player's kewl spell. But if a PC is facing a monster with a similar ability and cleverly comes up with using shocking grasp I'll likely allow it.

But that's because my players are not the rules lawyer sort or the optimizer sort. So thwy wont take that ruling and use it against another ruling later. As a DM I consider it one of my jobs to make sure the players get some opportunity to use the fun stuff their PCs can do and I try to avoid seeming to pull stuff out of the ether that denies them that.

My general rule of thumb is if it works for the PCs, it also works for the monsters. If my players' characters can shut down the fun stuff monsters can do, then the monsters should be able to do likewise. I'm not pulling anything out of the ether to do it, just the game rules. The problem I face up against is that my players include many of the types that yours do not, and they will rigorously use any rules and rulings to their advantage while conveniently forgetting those rules and rulings if applied by monsters to their PCs.

The subject of this thread is a case in point, as is your hellish rebuke example. The group in question has been willing to argue that SG shuts down reactions so Shield, UD, and Hellish Rebuke are all unusable by the NPCs they have assaulted and yet they have also argued that SG should not shut down their own versions of such since [insert all arguments as to why not already echoed here].

So yeah what's good for the goose is good for the gander and all that.

 

[Ovinomancer]

There is a difference between a player rolling a 'hit' and the character actually being struck. One is merely a game mechanic (upon which other game mechanics may depend) and the other happens to a creature in-game.

The shield spell, and the game mechanics involved, doesn't represent the creature being hit in-game and then casting shield and them time rewinding in-game. It represents the fact that the creature would have been hit if he hadn't interposed a magical shield of force in the nick of time, preventing the creature ever being hit at all in-game!

Of course it doesn't. No one's claimed otherwise. In fact, for your assertion to take place, you'd have the narration of the mechanical results occur immediately after any partial resolution, which isn't how I've ever seen it done. I suppose you can posit that someone out there starts narration in the middle of a mechanical resolution, and so would have this problem, but it's not a problem for anyone I've seen post here.

The 'hit' mechanic really represents that the creature will be hit, unless the creature can do something about it! Most of the time it can't, and then the creature is actually hit in-game and the effects of the hit are applied. However, some of the time, the creature can do something about it (shield, Uncanny Dodge, Relentless Rage, etc.) and this means that the creature was never affected by what the hit would have been and is instead affected by the attacking effect modified by the reaction. The game mechanic of a 'hit' triggers the reaction, and the effects of being hit (damage, reaction-denial, whatever) are only applied after the reaction.

No, if the attack is successful, the mechanic says that a hit has occurred. You may not narrate that hit until you finish the other parts of the mechanical resolution, such as reactions to the hit that may modify it like shield, but the hit occurs. If it does not yet occur, you cannot react to it mechanically. You're confusing the narration of the in-game events with the mechanical resolution -- they're not the same thing. The narration serves the mechanical outcome, the mechanics are not beholden to the narration.

So, as you note, in the case of shield, a hit must occur. "Must" because you cannot react otherwise. The you choose to react, if able. And, if that reaction is shield, and it successfully negates the hit, then the narration follows that the hit didn't occur, because that's the result in the game fiction. Mechanically, though, the hit did occur but was negated by the shield reaction. That's the beauty of the mechanics/narration divide -- the mechanics don't need to make narrative sense during resolution, only their final outcome needs to provide narrative sense. The shield outcome provides narrative sense, but the resolution process does not. This is true for any shield spell usage -- it doesn't make narrative sense to narrate the resolution process, it only makes sense to narrate the outcome of the resolution process. We don't need a nice story that walks alongside the mechanics, just mechanics that provide as outcome a nice story.

So, with shield and shocking grasp (or any other reaction to a hit and shocking grasp), the mechanical effects are that the hit occurs. On a hit, shocking grasp negates reactions and does some damage. 5e doesn't have an order of operations that separates these effects -- the effects of a hit don't have a wait delay for an reaction before applying their effects. So the effects of the shocking grasp, including the prohibition on reactions, are in place before a reaction can be declared.

We know that Uncanny Dodge must work that way. You say that reaction-denial is an effect of being hit, but so is being damaged! But the effects of being hit are only actually applied to the target after Uncanny Dodge has already modified it, and those effects include BOTH damage AND reaction-denial. If those effects were actually applied before the reaction modifies it then it would be Uncanny Healing, and we know that it doesn't work that way.

Yes, so is damage. Sense we don't need the resolution process to make narrative sense, this is fine. You can have the full damage dealt, but then have Uncanny Dodge modify that damage before it's applied, because only the outcome needs to make narrative sense. Uncanny Dodge makes perfect narrative sense when use to narrate the end result of the resolution process -- you take half of the damage. But if you're hit with Shocking Grasp, that full damage and the prohibition against reactions are in place before the reaction can be declared -- they're fully attendant to the hit. So you can't react to a successful Shocking Grasp spell because the hit removes your ability to react. It would also remove your ability to cast the Shield spell as a reaction. Both make full narrative sense in their results.

 

[Ovinomancer]

IMO Uncanny Dodge applies before the Shocking Grasp affect takes hold.

My visual interpretation... An electrically charged hand (SG) is about to touch you, you attempt to avoid being hit in a critical area (UD). The attack still manages to hit you but you don't take the full damage because you managed to dodge the brunt of it. So instead of taking a shocking attack to the chest you manage to be grazed on the arm or something. You take less damage and then at the end when the damage is rolled you suffer the reaction nullifying affects of Shocking Grasp.

IMO UD happens in between the attack roll and the damage roll. You know you're going to be hit and you can't stop that from happening, but you can attempt to less the impact by adjusting yourself and dodging somewhat.

I think the error here is that you have a preferred narration that you're making the mechanics adapt to. There are many other narrations of the effects of Uncanny Dodge that don't have your particular set of baked in biases (not a bad thing, just a thing). In that sense, you're now making the mechanics work for a preset narration instead of narrating the results of the mechanics.

Which, again, is fine. Rulings, not rules.

 

[Uller]

So you can't react to a successful Shocking Grasp spell because the hit removes your ability to react. It would also remove your ability to cast the Shield spell as a reaction. Both make full narrative sense in their results.

I've mentioned this a few times and no one has answered (or I missed it)

What about a hit that paralyzes the target...say, from a ghoul? Paralysis prevents reactions. So you can't react to the hit so you can't use UD or Hellish Rebuke etc because (following your logic) the hit happened and they dont negate the hit. The effects of the hit prevent reactions so therefore you can't react to a ghoul's attack if you fail your save.

Also...what about the case where shield DOES NOT negate the hit from shocking grasp? How does your logic apply then? Shield could never have been cast at all?
This isn't really a hypothetical. If you know that you won't be able to use reactions and a hill giant is about to smack you then you want to cast shield even if it won't negate the hit...