Rules Question: Illusory Wall

[JohnnyO]

Can someone clarify how Illusory Wall works exactly? I recently ran a fight where the party was up against a dragon.

Using some forced movement, they backed the dragon up against the wall and then the wizard cast Illusory Wall, trapping him there, it looked something like this (W= normal wall, D=dragon, I = Illusory Wall)

W W W W
I D D I
I D D I
I I I I

Now, because the wizard has a decently high intellect, the dragon was trapped there for the rest of the encounter, and the party quickly surrounded him and butchered him.

I'm very impressed with the parties tactics in the battle, but when they saw how effective it was, their eyes immediately lit up at using this tactic in the future against various boss monsters, so I want to make sure I have the rulings right when it comes up again.


1) The Illusory Wall attack is supposed to happen when the enemy moves adjacent to the wall, but what about when he is already adjacent? Can the caster continue to make the attack each round and trap a creature till the end of the encounter (assuming high enough rolls?) Or can the creature simply escape after the first turn without an attack, since he hasn't "moved adjacent"?


2) And for future reference, from a DMs perspective, whats a good action for a boss monster stuck inside an illusory wall to do? It felt kind of anticlimactic after a long battle for the dragon to basically give up his turns because he couldn't see anything to attack attack and couldn't move anywhere

 

[Aegeri]

1) The Illusory Wall attack is supposed to happen when the enemy moves adjacent to the wall, but what about when he is already adjacent? Can the caster continue to make the attack each round and trap a creature till the end of the encounter (assuming high enough rolls?) Or can the creature simply escape after the first turn without an attack, since he hasn't "moved adjacent"?

No, the wall requires the enemy to move adjacent. If the dragon started its turn adjacent, no attack is made and it can march through with no issue. Move adjacent means "moved adjacent" with a shift or a move action. See wall of fire for example:

Any creature that starts its turn adjacent to the wall takes 1d6 + Intelligence modifier fire damage.

In this case starting your turn provokes the walls wrath, moving into it causes damage as well. Moving into it and starting your turn adjacent are specific wording, so that is important to bear in mind in this case.

2) And for future reference, from a DMs perspective, whats a good action for a boss monster stuck inside an illusory wall to do? It felt kind of anticlimactic after a long battle for the dragon to basically give up his turns because he couldn't see anything to attack attack and couldn't move anywhere

Nothing, because it's not as powerful as you probably ruled it to be. Unless they can force the dragon away, beyond the first turn no attack is made and the dragon can march through without issue.

 

[mneme]

Also, note that Illusory Wall blocks line of sight -- -not- line of effect. The dragon may not be able to move through the wall (particularly if people keep knocking it back), but if there are creatures making melee attacks against it, it -can- (blindly) attack back, sucking up the -5 penalty. Moreover, on rounds where it has a breath weapon, it can breathe through the wall without penalty.

That said, Illusory Wall is very effective, though it is a daily power. For true (broken) stupidness, try using Improved Tome of readiness to be able to use it in -every- fight in paragon levels.

 

[Aegeri]

Also, note that Illusory Wall blocks line of sight -- -not- line of effect. The dragon may not be able to move through the wall (particularly if people keep knocking it back), but if there are creatures making melee attacks against it, it -can- (blindly) attack back, sucking up the -5 penalty. Moreover, on rounds where it has a breath weapon, it can breathe through the wall without penalty.

That said, Illusory Wall is very effective, though it is a daily power. For true (broken) stupidness, try using Improved Tome of readiness to be able to use it in -every- fight in paragon levels.

Until the DM has monsters immune to illusion

Then you're boned when your tactic falls apart instantly. Also note that blindsight instantly defeats the wall as well, because it doesn't block line of effect so they can still "see" anything through the wall. So the DM certainly has options when it comes to this and as you said, bursts/blasts aren't worried in the least.

I also made a monster once that could switch the effects of zones or conjurations from ally/enemy and who was controlling it. So it could change an enemies wall or zone into one that was under its control until the end of its next turn (on a successful will attack). That can be quite the hilarious power when the wizards flaming sphere goes rogue on him.

 

[Xeterog]

So, your dragon couldn't fly? (and if the dragon was in a room that only had a 20' ceiling, something seems off

 

[Stumblewyk]

I'd have had the dragon fly directly upwards, and out of the walled-in area. Unless terrain made this impossible, of course.

 

[mneme]

Until the DM has monsters immune to illusion

Then you're boned when your tactic falls apart instantly.

*blink* Really? So losing a crazy trick that you can do 1/encounter for a utility slot and a feat means you don't have anything else to do all day? I'm pretty sure most wizards build differently than that.

Also note that blindsight instantly defeats the wall as well, because it doesn't block line of effect so they can still "see" anything through the wall.

True...except that the primary effect of the wall is actually to prevent the target from closing to melee. So the fact that the target can see through it isn't really relevant unless it's artillery or the like (in which case, the right thing to do is put a melee person or two right inside the wall with it, and use the wall to prevent it from escaping.

 

[JohnnyO]

If you are interested, I was the encounter from P1: King of the Troll haunt Warrens, and there were in fact 20' ceilings.

He was mostly using his aquatic abilities to fight from the deep water, but they were able to pull him on land using forced movement, then lock him down. I eventually had him fly to the cieling and the party the party negotiated a deal after the stalemate.

However, I want to be prepared for when this encounter inevitably happens again

 

[frogged]

Using some forced movement, they backed the dragon up against the wall and then the wizard cast Illusory Wall, trapping him there, it looked something like this (W= normal wall, D=dragon, I = Illusory Wall)

W W W W
I D D I
I D D I
I I I I

You and your players are missing a very important part of all Wall powers:

A wall fills a specified number of contiguous squares within range, starting from an origin square.
-PHB pg 272

Illusory Wall is a Wall 8 power. That wall the wizard created around the dragon across 8 squares is only 5 feet (1 square) high. If your wizard wants , he would need to trade off some length to make a taller wall by stacking some of the 8 squares. This is alluded to in the rest of the Wall rules entry:

Each square of the wall must share a side—not just a corner—with at least one other square of the wall, but a square can share no more than two sides with other squares in the wall (this limitation does not apply when stacking squares on top of each other).
-PHB pg 272

With only a 5 foot wall in front of it, the dragon can attack over the low wall (since it probably has reach 2 or better) or could simply fly out of the corner. Other creatures trapped behind a seemingly solid wall might try to climb it.

 

[Bold or Stupid]

You and your players are missing a very important part of all Wall powers:

Illusory Wall is a Wall 8 power. That wall the wizard created around the dragon across 8 squares is only 5 feet (1 square) high. If your wizard wants , he would need to trade off some length to make a taller wall by stacking some of the 8 squares. This is alluded to in the rest of the Wall rules entry:

With only a 5 foot wall in front of it, the dragon can attack over the low wall (since it probably has reach 2 or better) or could simply fly out of the corner. Other creatures trapped behind a seemingly solid wall might try to climb it.

Nope the wall is up to 4 squares high.

Illusory Wall

A seemingly solid wall materializes before your foes, dividing the battlefield with your convincing illusion.

Daily Arcane, Illusion, Implement
Standard Action Area wall 8 within 20 squares

Effect: You create the illusion of a contiguous wall of solid material (stone or metal, for example). The wall can be up to 8 squares long and 4 squares high, and it lasts until the end of your next turn. The wall blocks line of sight for all enemies (but not your allies). When any enemy moves adjacent to the wall, you can make an attack (Intelligence vs. Will) against that target; if successful, the target cannot move through the wall on its current turn, but it can try again on later turns. On a miss, the wall no longer blocks line of sight or movement for that creature.

Sustain Minor: You can sustain this power until the end of the encounter.