"enter your reach" and polearm mastery

[brehobit]

How does the text in polearm mastery about "enter your reach" work with cover? Assume a reach weapon is being used.

If a creature was 10 feet away but behind full cover and then steps so that it no longer has cover (at either 5 feet or 10 feet), does that trigger an opportunity attack?

"...other creatures provoke an opportunity attack from you when they enter your reach."

 

[Li Shenron]

Mmm... difficult!

I need to think about what does the ability means in narrative terms. It works with weapons that have 10ft reach or with the quarterstaff. With those weapons you can strike anyone also at 5ft. The feat's ability however grants an OA only when an enemy enters your reach, not if it moves within your reach (or "threatened area", to use an older edition term). So I'd say that the feat's ability has something to do with using the tip of such weapons, something that occurs exactly at that distance, and nothing to do with the fact that the enemy moves from a non-targettable position to a targettable position (for example, you don't get an OA if someone teleports directly 5ft from you).

So my conclusion is that in a situation where e.g. there is a large column in front of you (5ft away) and an enemy pops out of the cover provided by the column (e.g. moving sideways) but doing so means it moves from 10ft away to again 10ft away from you, then you don't get an OA.

Edit: from a RAW perspective, perhaps this ruling could be justified by saying that reach isn't blocked by cover, so if a target is both within reach and behind cover, it still counts as 'within reach' (ditto) even tho total cover makes it non-targettable

 

[Jester David]

For the text of opportunity attacks, you need to be able to see the creature to make the OA. So invisible creatures don't provoke. If you're behind total cover or heavily obscured, you can't be seen. So while you're entering the reach and technically triggering the OA, the polearm fighter can't make the attack.

When stepping out from behind cover, they're not entering your reach. They're technically moving inside it.

 

[brehobit]

I've only started using this feat and the issue has come up 2 or 3 times per session. It seems like folks must have encountered this issue before (folks around a door, etc.).

The whole thing feels wonky. But as written I *think* what you have is correct Li Shenron.

 

[bid]

How does the text in polearm mastery about "enter your reach" work with cover? Assume a reach weapon is being used.

If a creature was 10 feet away but behind full cover and then steps so that it no longer has cover (at either 5 feet or 10 feet), does that trigger an opportunity attack?

"...other creatures provoke an opportunity attack from you when they enter your reach."

Nice question.

If you forget movement, a creature is either in reach or out of reach. A creature behind cover is out of reach while an invisible creature is in reach.

The way I see it, you get an OA when the creature moves from "out" to "in". The fact that it was "out" at 15' and now "in" at 10' is a consequence, not the cause.

 

[Harzel]

(for example, you don't get an OA if someone teleports directly 5ft from you).

...

Edit: from a RAW perspective, perhaps this ruling could be justified by saying that reach isn't blocked by cover, so if a target is both within reach and behind cover, it still counts as 'within reach' (ditto) even tho total cover makes it non-targettable

While I think I agree with the way you would rule, that last bit works for cover but doesn't justify the teleportation scenario.