Thoughts/observations on passwall

[hapro]

This seems to be a fairly undocumented feature so I was wondering if people noticed anything about the behavior of monsters inside walls.

The first thing I noticed was that monsters in walls are visible even if the room is filled with darkness. This kinda struck me as an oversight and a feature at the same time. Walls cannot be covered in darkness, so monsters inside walls are always visible if you're within 1 tile of the wall. Perhaps dungeon walls have very tiny torches on them that illuminate the walls. Even if you have a pillar surrounded by 8 tiles of darkness, the wall will still be illuminated.

The second thing that I haven't confirmed is I don't think monsters are capable of casting spells (or maybe using any special abilities at all?) from inside a wall. Tactic or exploit?

Late-game spoilers:

My second Andy fight resulted in him summoning, then casting darkness, then walking next to me, but the tile he walked on was a wall. At this point, he proceeded to engage in a melee battle to the death with me, never teleporting or summoning any more monsters, and I didn't have to worry about a light source as I could still see him.

[Blank4u47]

Interesting, however a player ghost would no longer drop his items inside the wall like in older versions. And that's where I'd use that tactic.