D&D 5E How broken is tunneling speed?

[Stalker0]

It’s true that the OA would be from the original square, hence total cover would not matter. Same idea as if someone moved away from you into fog, the fog doesn’t affect the OA if they weren’t in it when they started movement.

however thst belies the point as someone noted above. The initial 5 ft burrow down doesn’t generate the OA to begin with, as you haven’t left reach. It’s only on the second piece of 5 foot movement (going further underground or away from the person) that would generate the OA, and at that point you would have total cover.

 

[Voadam]

Assuming we are talking about grid combat and not TotM, the attack must occur while the target is still in the initial square. That's why the Sentinel feat works. Sentinel doesn't "pull back" the target, it drops it's speed to 0 and prevents it from leaving it's square.

Opportunity attacks only make sense if you can attack before the opponent is completely out of reach. It doesn't make any difference if the movement is horizontal or straight down with burrowing.

Right, the last square they are still in reach. Not necessarily the first one.

So if they start on the left in reach, run around you to your right and leave reach on your right, you attack them on the square to your right interrupting them right before they leave that square and not the initial one on your left.

When someone is next to you and moves down one square they are still in the 3d cube of reach and so do not provoke, when they are underground five feet and go down five more feet that would be when they leave your reach, not the initial square cube on the surface.

 

[Nefermandias]

Right, the last square they are still in reach. Not necessarily the first one.

So if they start on the left in reach, run around you to your right and leave reach on your right, you attack them on the square to your right interrupting them right before they leave that square and not the initial one on your left.

When someone is next to you and moves down one square they are still in the 3d cube of reach and so do not provoke, when they are underground five feet and go down five more feet that would be when they leave your reach, not the initial square cube on the surface.

Yes, you are right about the attack occuring on the last square adjacent to you. So I don't see how burrowing would prevent the opportunity attack?

 

[Voadam]

Yes, you are right about the attack occuring on the last square adjacent to you. So I don't see how burrowing would prevent the opportunity attack?

Because you can't attack the adjacent square diagonally down from you in the grid cube you threaten because your attack is blocked by the ground.

Unless you are a ghost or something like that.

Normally the grid is only concerned with 2d movement, but we are introducing 3d movement with burrowing and incorporeal flying ghosts.

Otherwise burrowing straight down from adjacent to you does not leave the infinitely vertical square adjacent to you and does not provoke.

 

[Nefermandias]

Because you can't attack the adjacent square diagonally down from you in the grid cube you threaten because your attack is blocked by the ground.

Unless you are a ghost or something like that.

Normally the grid is only concerned with 2d movement, but we are introducing 3d movement with burrowing and incorporeal flying ghosts.

Do the ground really block the attack though? I'd be under the impression that it only provides cover? Same as attacking someone around the corner of a stone wall.

EDIT: It shouldn't be a big deal, really. 3d movement has always been present in my games since forever...

 

[MarkB]

Do the ground really block the attack though? I'd be under the impression that it only provides cover? Same as attacking someone around the corner of a stone wall.

EDIT: It shouldn't be a big deal, really. 3d movement has always been present in my games since forever...

If the burrower is not leaving a tunnel, they become completely surrounded by earth the moment they enter that square diagonally down from you.

So when they try to leave that square and would provoke an opportunity attack from you, you can no longer see them. And you can only make opportunity attacks against creatures you can see.

 

[Nefermandias]

If the burrower is not leaving a tunnel, they become completely surrounded by earth the moment they enter that square diagonally down from you.

So when they try to leave that square and would provoke an opportunity attack from you, you can no longer see them. And you can only make opportunity attacks against creatures you can see.

That makes sense.

 

[Rabulias]

Burrowing without a tunnel is effectively the same as incorporeal in effect for this discussion, like a ghost who drops down 5 feet into the ground in front of you.

By a twisting of the written rules (but maybe not RAI), they are both technically leaving your reach in that you cannot reach them (blocked by the ground). Converting this to 2D, imagine an orc (O) standing at the end of a narrow stone wall, fighting a goblin (G) diagonally adjacent to the orc like so:

O____wall
....G

If the orc steps to the right, so the wall is between it and the goblin, is an Opportunity Attack provoked?

EDIT: Added periods in front of the goblin to show spacing.

 

[Nefermandias]

Burrowing without a tunnel is effectively the same as incorporeal in effect for this discussion, like a ghost who drops down 5 feet into the ground in front of you.

By a twisting of the written rules (but maybe not RAI), they are both technically leaving your reach in that you cannot reach them (blocked by the ground). Converting this to 2D, imagine an orc (O) standing at the end of a narrow stone wall, fighting a goblin (G) diagonally adjacent to the orc like so:

O____wall
G

If the orc steps to the right, so the wall is between it and the goblin, is an Opportunity Attack provoked?

Orc stills technically adjacent, so no opportunity attack is provoked.

 

[Mistwell]

Over the years there's been plenty of discussion about the effect of fly speed on games. Some DMs are fine with 1st level PCs having it right out of the gate (aarokocra, tiefling variant, etc) while others prefer it be limited in order to shut down encounter-circumventing tactics. In 4e, flight was very limited because the designers believed that easy access to flight negated to many common encounter tropes.

I'm building homebrew classes and was looking at tunnel speed (Edit: i meant burrow speed). It seems super duper extra OP, especially when combo'ed with something like cunning action disengage. Has anyone experienced PCs with tunnel speed at their table? Was it broken? What do you feel would be a good level to start allowing PCs access to tunnel speed?
View attachment 143771

EDIT: Burrowing speed. I mean burrowing without making a tunnel.

I am not sure how broken it would be but I did want to mention I think it's very cool and worth figuring out how to make it work .I love the idea of a D&D playable race that can burrow.

At this point, I'm leaning at leaving out all burrow speed because I imagine disengage being abused and characters being effectively invulnerable when it's not their turn

Aw, I hope you find a way to make it work. I think this would be a very fun thing to play, and would result in countless stories to tell about your game, and is worth figuring out how to balance it.

What if you required a bonus action to activate burrowing? That would cease the use of cunning action.