D&D 5E Using booming blade on a reaction attack with sanctuary question

[Maxperson]

Well unless you have forced movement on that AO then they can stop or move right back where they started utilizing the same movement. The rules for AOs are about the attempt not resolution of movement. Its worded like crap yes but editing is a nightmare throughout 5e. It's the shield spell paradox all over.

They cannot stop, because they have already left reach. The trigger for the AOO is, "moves out of reach," not "is about to leave reach." The attack happens right as the enemy is leaving, but that attack is not triggered until the enemy is out of reach. It interrupts the movement only to allow the attack, not to allow the enemy to change it's mind. Essentially the enemy is in mid step when it gets hit and then the step completes and it is in the new square. At that point the enemy can walk back or do whatever.

 

[Charlaquin]

Also the Devs say Booming Blade works with War Caster


And explains their reasoning here

Jeremy Crawford is just a man, giving his interpretation of the rules. This can help us understand what the design intent may have been (for whatever that’s worth given that he has demonstrated design intent is subject to change), but it doesn’t mean that’s the only valid reading of rules written in natural language.

 

[Maxperson]

No the Opportunity Attack trigger is when it moves out but occur before it.

Not by RAW.

"You can make an opportunity attack when a hostile creature that you can see moves out of your reach."

That is the trigger. The attack timing is not the trigger.

Otherwise dying from it or being otherwise unable to move after it would invalidate the trigger.

No it wouldn't. The creature would die 5 feet away from you as it's momentum places it in the square it moved to, and Sentinel just renders the rest of the creature's movement 0, stopping it 5 feet away. Or if you have a generous DM, specific can beat general and stop it before it leaves the square, but it's still a specific exception.

What DOES invalidate the trigger is the creature deciding not to leave reach, since leaving reach is the RAW trigger.

 

[Stoutstien]

Yeah, logically AOOs should be triggered by entering the reach of a target with a longer weapon (say, reach > two-handed > versatile > any other melee weapon). But would that lead to better gameplay?

I use something similar and I would say 100% it's better. It makes charging at each other risky.

*Basically of you want to enter the reach of someone with a melee weapon you either eat an AO or cut speed in half to cover your approach. Moving within reach will also trigger AOs for certain classes unless they treat that space as DT. Moving away doesn't besides for barbarians who can basically follow them and smack them with an AO.
An additional rule with this is of you can flank a target you can bypass most of this.
So melee combat is about more than soaking hits. It's denial and control without just slapping magic on it.**

 

[Plaguescarred]

Jeremy Crawford is just a man, giving his interpretation of the rules. This can help us understand what the design intent may have been (for whatever that’s worth given that he has demonstrated design intent is subject to change), but it doesn’t mean that’s the only valid reading of rules written in natural language.

Correct its just an interpretation from the Devs, which i based to make my own. People are free to rule how they want.

 

[Maxperson]

Correct its just an interpretation from the Devs, which i based to make my own. People are free to rule how they want.

I don't give Crawford much weight. The man literally said that See Invisibility which says, "For the duration, you see invisible creatures and objects as if they were visible" doesn't stop the disadvantage when attacking that invisible person and doesn't really let you see the creature clearly.

 

[Charlaquin]

The problem here is that the wording on opportunity attacks suggests that the attack happens before the thing that triggers it. You can make an opportunity attack when the creature leaves your reach but the attack occurs just before the creature leaves your reach. That means either the attack must occur retroactively, just before the event that (will) trigger it, or the trigger must actually be the announcement of intent to move to a position that is outside your reach, rather than the actual movement itself. In the latter case, we must consider what happens if the results of the opportunity attack change circumstances such that the target no longer wishes to resolve the announced movement. A DM could either rule that the target must complete the announced movement, or that they can decide not to do so; the rules don’t indicate a preference for either approach as far as I can tell.

 

[Plaguescarred]

Not by RAW.

"You can make an opportunity attack when a hostile creature that you can see moves out of your reach."

That is the trigger. The attack timing is not the trigger.

Its exactly what i said ''the Opportunity Attack trigger is when it moves out but occur before it.''

What you said was that the trigger was '''has left reach''. It's not

But it can only happen if the creature actually leaves reach. You don't have the AOO if the creature doesn't leave reach. Only the attack happens before the creature leaves reach, not the trigger. The trigger is "has left reach." No leave reach, no trigger.

 

[Charlaquin]

I use something similar and I would say 100% it's better. It makes charging at each other risky.

*Basically of you want to enter the reach of someone with a melee weapon you either eat an AO or cut speed in half to cover your approach. Moving within reach will also trigger AOs for certain classes unless they treat that space as DT. Moving away doesn't besides for barbarians who can basically follow them and smack them with an AO.
An additional rule with this is of you can flank a target you can bypass most of this.
So melee combat is about more than soaking hits. It's denial and control without just slapping magic on it.**

Ooh! I love the addition that flanking allows you to approach without provoking an OA! That makes flanking a relevant concern again, without being as overpowered as granting advantage!

 

[Stoutstien]

Ooh! I love the addition that flanking allows you to approach without provoking an OA! That makes flanking a relevant concern again, without being as overpowered as granting advantage!

Once I get home I'll pull out the list of changes I made and start a new thread.