Ceiling
The ceiling is a part of the dungeon where certain monsters or traps can be located. Some special levels (such as some Quest home levels, the Plane of Air, and the Plane of Water) do not have a ceiling. In those cases, NetHack substitutes different flavor text. [1].
Contents
Monsters
Only five monsters use the ceiling.
- p rock piercer
- p iron piercer
- p glass piercer
- t lurker above
- q wumpus
Piercers and lurkers above hide on the ceiling until something stumbles onto their square. A hard helm will protect the player from a piercer's damage, but beware that pets will be instakilled by lurkers. Because wumpuses' feet stick to the ceiling, they can move over water tiles without drowning.
Prior to NetHack 3.6.0, the game considered t trappers to hide on the ceiling. This was bug C342-51 in NetHack 3.4.3.
Traps
When stepping on a falling rock trap, a rock falls from a trapdoor in the ceiling.
Items
A drum of earthquake, when improvised, will unhide any monsters hidden on the ceiling.
Applying a bullwhip, an expensive camera, or a mirror up will produce a message about the ceiling.
Quaffing a cursed potion of gain level causes you to "rise up, through the ceiling" unless you are in Sokoban, Fort Ludios, the home level of the Quest, the top floor of Vlad's tower, the top floor of the Wizard's tower, on dungeon level 1 without the Amulet of Yendor, or in the endgame.
Quaffing a cursed potion of levitation produces the message "You bump your head on the ceiling" and damages you.
Reading a scroll of earth produces the message "The ceiling rumbles around you!" and creates several boulders.
Zapping a wand of digging or the dig spell upwards will cause a rock to fall on your head, but attempting to dig by any other means has no effect since you are unable to reach the ceiling.
Other
There is a 1⁄4 chance that you may trigger a special type of trap door when kicking a throne. The message when this happens is, "The floor opens up under you!" followed by "The hole in the ceiling above you closes up." This is the only method of triggering this trap.
Variants
SLASH'EM
No new traps are present in SLASH'EM, but rust traps will become fountains when untrapped. It is not clear if they are still considered ceiling traps.
SporkHack
SporkHack introduces ceiling collapse traps, which drop several boulders onto the player.
xNetHack
In xNetHack, some levels (including most quest levels) are flagged as "outdoors". Scrolls of earth do not work on outdoor levels, and ceiling traps such as rust and falling rock traps won't generate. Throwing an object upwards will also not be shown as hitting a ceiling.
References
