D&D 5E Reacting to Movement

[Voadam]

No, because that's not what's happening. The pressure plate activates when you step on it in this example.

Since you only provoke an opportunity attack after you leave someone's reach, a more appropriate analogy would be that there is a section of floor covering a pit that normally has some kind of locking mechanism to keep people from falling through. If you hit the pressure sensor, however, that lock is disengaged, and so, after leaving the section of floor it is located on, and then stepping on the now unlocked floor panel, stepping on it causes it to swing open and you fall.

Of course, in D&D, such a trap would probably allow for a Dexterity save, so an even more appropriate analogy would be, that, instead of a pit trap, there's a glyph of warding that explodes when you step on it. Either way, you can't look at it as "oh, I was moving, and that guy's sword is in front of me, I better stop".

You committed to moving, knowing you would provoke an opportunity attack from a foe whose space you are leaving. And then you got hit by it. Any rider effect attached to that attack that could prevent your movement certainly has it's normal effect, but you are still committed to leaving the attacker's reach. If you hadn't done so, or intended to do so (in the case of movement prevention), there wouldn't have been an opportunity attack in the first place.

And for all the "I only move a fraction of 5 feet" statements, if you're not 5' away, you haven't left the attackers reach.

So if you are running and part way through your movement you notice you hit a pressure sensor, can you stop?

Normally under 5e rules I think you can run up five feet, swing your sword at someone, then decide whether you are going to keep going or not based on whether you kill that enemy. You can do this multiple times if you have multiple attacks.

The interrupt preventing the trigger of the interrupt is inherent in the nature of the attack of opportunity timing and interrupt nature.

If you get knocked prone leaving someone's threatened space and you still have movement I would think you can decide to crawl or to get up and keep going on your feet or not keep going.

If you provoke an attack for leaving the threatened space that gets resolved before you leave the space, if it prevents you from moving (grappling, paralysis, magically stopped, etc.) then you never actually get to the trigger action.

 

[Lycurgon]

After you have been hit with an OA, which happens before you have moved a square/5', you can choose to stop. If you stop you do not take the damage.
You have to try to leave your square but after the OA, the situation has changed and you can change your mind based on the new situation.

This is RAW and Jeremy Crawford supports this, you can read his tweet about it here: Can I decide not to move out of reach after the Opportunity Attack?

You are free to ignore RAW and rule however you like, but nothing in the rules stops you changing your mind and not completing your intended movement after the change in circumstances.

 

[Swarmkeeper]

After you have been hit with an OA, which happens before you have moved a square/5', you can choose to stop. If you stop you do not take the damage.
You have to try to leave your square but after the OA, the situation has changed and you can change your mind based on the new situation.

This is RAW and Jeremy Crawford supports this, you can read his tweet about it here: Can I decide not to move out of reach after the Opportunity Attack?

You are free to ignore RAW and rule however you like, but nothing in the rules stops you changing your mind and not completing your intended movement after the change in circumstances.

That's a rather... flexible interpretation of what JC said.

Typically, you don't get "take backs" just because something unfortunate is happening to you.

But feel free to rule how you like at your table.

 

[James Gasik]

After you have been hit with an OA, which happens before you have moved a square/5', you can choose to stop. If you stop you do not take the damage.
You have to try to leave your square but after the OA, the situation has changed and you can change your mind based on the new situation.

This is RAW and Jeremy Crawford supports this, you can read his tweet about it here: Can I decide not to move out of reach after the Opportunity Attack?

You are free to ignore RAW and rule however you like, but nothing in the rules stops you changing your mind and not completing your intended movement after the change in circumstances.

So despite the fact that RAW says clearly you have to leave someone's reach to provoke, Jeremy says you can provoke an opportunity attack without actually acting on the trigger? Because "trying to leave someone's reach" isn't what the book says.

If the RAI is that, the text should say that. That way, when someone asks me a question, I can go by what the text says, not go looking for some developer tweet to explain to me "well no, actually what we meant was..."

 

[NotAYakk]

You committed to moving, knowing you would provoke an opportunity attack from a foe whose space you are leaving. And then you got hit by it. Any rider effect attached to that attack that could prevent your movement certainly has it's normal effect, but you are still committed to leaving the attacker's reach. If you hadn't done so, or intended to do so (in the case of movement prevention), there wouldn't have been an opportunity attack in the first place.

And for all the "I only move a fraction of 5 feet" statements, if you're not 5' away, you haven't left the attackers reach.

Except, the OA occurs the moment you leave reach.

And the booming blade triggers after you move 5'.

This means that the person hit with the OA has a full 5' to say "ok, maybe I shouldn't move" after leaving reach to avoid the damage.

Usually the 5' units don't matter much. But if there is a 3' wide path on the floor, you can walk along that path. You aren't forced to take 5' steps and miss it.

Similarly here; usually, 5' is how far you move, and in fact on the grid you require people to end their movement in the middle of the grid. But when that 5' grid leads to a ridiculous problem (they know they are going to take damage 5' before they take it, but cannot stop because they aren't allowed to move 1" and reverse course), you should use the grid the less than fully.

Remember, the grid is an optional rule intended to simplify things. It isn't the core combat engine. When it leads to ridiculous results, you are supposed to discard it.

 

[Voadam]

So despite the fact that RAW says clearly you have to leave someone's reach to provoke, Jeremy says you can provoke an opportunity attack without actually acting on the trigger? Because "trying to leave someone's reach" isn't what the book says.

If your attack of opportunity kills the enemy they do not make it out of your reach and never trigger it. The attack occurs before the creature leaves your reach, RAW.

"You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature. The attack occurs right before the creature leaves your reach."

This is inherent to the RAW OA timing resolution setup.

 

[James Gasik]

Except, the OA occurs the moment you leave reach.

And the booming blade triggers after you move 5'.

This means that the person hit with the OA has a full 5' to say "ok, maybe I shouldn't move" after leaving reach to avoid the damage.

Usually the 5' units don't matter much. But if there is a 3' wide path on the floor, you can walk along that path. You aren't forced to take 5' steps and miss it.

Similarly here; usually, 5' is how far you move, and in fact on the grid you require people to end their movement in the middle of the grid. But when that 5' grid leads to a ridiculous problem (they know they are going to take damage 5' before they take it, but cannot stop because they aren't allowed to move 1" and reverse course), you should use the grid the less than fully.

Remember, the grid is an optional rule intended to simplify things. It isn't the core combat engine. When it leads to ridiculous results, you are supposed to discard it.

But when reach is specified as 5', is it really optional?

 

[James Gasik]

If your attack of opportunity kills the enemy they do not make it out of your reach and never trigger it. The attack occurs before the creature leaves your reach, RAW.

"You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature. The attack occurs right before the creature leaves your reach."

This is inherent to the RAW OA timing resolution setup.

Yes, the effect of an opportunity attack can void the triggering circumstance. But all I'm saying is, that should be the only thing that should be allowed to do so. You shouldn't be able to decide not to do the thing after the consequences of doing the thing are known.

That'd be like saying "oh, that opportunity attack is a crit and will kill me, Mr. DM, I'm just going to stand still instead."

 

[Voadam]

Yes, the effect of an opportunity attack can void the triggering circumstance. But all I'm saying is, that should be the only thing that should be allowed to do so. You shouldn't be able to decide not to do the thing after the consequences of doing the thing are known.

That'd be like saying "oh, that opportunity attack is a crit and will kill me, Mr. DM, I'm just going to stand still instead."

I think the intent of 5e combat rounds is that you can change as you go depending on circumstances such as the move attack then decide to either attack again or if you dropped them to then move again and attack someone else.

The opening attack with spell trigger seems like the pressure plate scenario. If you plan to go forward 30 feet and the DM says 15 feet in you hit a pressure plate I would think you can then stop at 15 or choose to keep going.

I don't think it is spelled out in 5e whether you declare at the beginning and no choice thereafter if things change part way through.

Here the combatant plans to leave the square and gets hit. That hit happens before they leave the square. The question is whether the combatant can change their mind about the rest of their movement now that they have been hit.

it seems a DM call as to whether reactions can happen quickly enough to no longer move to the next square and trigger the spell or whether they can stop themself from taking their foot off the pressure plate as they were moving.

I would stop them at that exact time and ask what they do under the changed circumstances.

 

[James Gasik]

I think the intent of 5e combat rounds is that you can change as you go depending on circumstances such as the move attack then decide to either attack again or if you dropped them to then move again and attack someone else.

The opening attack with spell trigger seems like the pressure plate scenario. If you plan to go forward 30 feet and the DM says 15 feet in you hit a pressure plate I would think you can then stop at 15 or choose to keep going.

I don't think it is spelled out in 5e whether you declare at the beginning and no choice thereafter if things change part way through.

Here the combatant plans to leave the square and gets hit. That hit happens before they leave the square. The question is whether the combatant can change their mind about the rest of their movement now that they have been hit.

it seems a DM call as to whether reactions can happen quickly enough to no longer move to the next square and trigger the spell or whether they can stop themself from taking their foot off the pressure plate as they were moving.

I would stop them at that exact time and ask what they do under the changed circumstances.

If that's what you feel the fairest way to handle a situation like this is, that'd be fine with me, were I playing at your table. But in my mind, the narrative thread is a little important- we have a scenario where X needs to occur before Y can occur- you need to provoke an opportunity attack before one can be made.

5e probably doesn't have the same strong language previous editions had regarding the ability of opportunity attacks to invalidate their trigger (I'm too lazy to check). But even lacking that, the problem I have here is that our hypothetical character was apparently OK with being hit by an opportunity attack when they decided to leave an enemy's reach.

But the instant someone says "attack happens and also", the player can say "no wait, I don't do that!"

I'm not usually an "action stated/action taken" kind of guy, but it occurs to me that nobody would be provoking opportunity attacks and suddenly freezing under normal circumstances. It's literally an instance of "oh no, I might take more damage! I don't want to move!".

Now upthread, someone posited the situation of "well, what if you were about to step into a space and it was lava, isn't it reasonable to stop moving?", and that would be fair, if the text for opportunity attacks didn't already point out that they aren't triggered until after you move. So to my mind, it's no different than if you provoked an attack, and a guy with Warcaster teleported you into a lava (or a Battlemaster with Pushing Attack punted you into one).