Special Tiles

While most of the dungeon is simply composed of stone and dirt, scattered throughout the dungeon are various more "interesting", materials and squares, both useful and hazardous.

Solids

For completeness, let's start with the normal squares, before continuing to the more unusual sorts:

Walls and Rock: The dungeon itself is carved out of unfinished rock. Within this, rooms and mazes are shaped of finished wall material. Neither of these are terribly interesting, but they can be dug through by various means, and the Stone to Flesh spell can convert these tiles into Mounds of Flesh.

Floors: Most of the dungeon floor is one of two types: "room" or "corridor" floor. "Room" areas are usually lit, while "corridors" rarely are, unless something is there to shed light. Otherwise, mysteriously lit corridors are a good hint that you've found a predefined room, likely with some Monsters in it. In general, if you convert some other tile into a floor (filling pits, etc.) you'll get a corridor tile.

Doors and Secret Doors: Room and corridor are often separated by doors, which can be opened or closed. Some monsters can open doors too, while others are too weak or too stupid to do so. Sometimes these are "secret doors", which are not visible until you search them out. The vast majority of monsters will never search for secret doors, so these will usually stymie them. You can turn a normal door into a secret door by zapping a Wand of Invisibility at it.

Blocked Doors: Many of the predefined rooms have "blocked doors". These appear identical to normal doors; the one difference is that monsters can't open them -- only you, the avatar can. This helps keep the room's inhabitants from escaping and wandering around the dungeon. But be warned, once you have opened a blocked door, it turns into a normal door, which monsters can go through freely.

Stairs: These allow access to other levels of the dungeon, for both you and the monsters. Note that stairs are considered "dungeon fixtures", and are essentially indestructible.

Ice: Ice poses no particular difficulties, except that it can be melted into water, perhaps unexpectedly. Digging downward can also break the ice, converting it to a water square. (Formerly, a Force Bolt could also do this, but no longer works as of version 113.)

Forest: A forest ("tree") tile blocks vision but not movement. In such a tile, you can also climb the tree, which lets you see through the forest, and also gives you a bonus for missile attacks against opponents on the ground. You will need to climb down before you can move elsewhere, and this will be automatic if you try to move out of the forest. The Animate Forest spell can temporarily convert a forest tile into a summoned pet.

Forest Fire: If you pass through a burning forest, you will take 3d3+6 fire damage per turn. Each turn, a forest fire has a 1 in 10 chance of completely burning, leaving a floor (corridor) square, and a 1 in 20 chance of producing smoke. As of version 117, Forest fire tiles cannot be animated.

Traps

Some squares are traps. Except for pits and spiked pits, all traps are more-or-less permanent fixtures in the dungeon. Many of these are hidden, but can be revealed by searching... or by falling into them! Monsters can also fall into traps, and this also reveals them to you. The types of traps are as follows:

Type	Trigger chance	Effects when triggered
Pit	40%	2d5 damage, stuck until you climb out
Spiked Pit	40%	3d5 damage, stuck until you climb out
Hole	30%	fall through to a random spot on the next floor
Smoke Vent	40%	creates a square of smoke
Poison Vent	40%	creates a square of poison smoke
Teleport Trap	90%	teleports you somewhere on the current level.

• You can create random traps with a Wand of Trapping. These will start out hidden (and you won't know what sort you've created), but you can search for them like any other trap.
• You can hide a visible trap by zapping it with a Wand of Invisibility.
• Traps are particularly rough on mice, who have consistent routes.
• Pits can be created by the Dig or Create Pit spells, and and will also be left behind if a water or acid square is boiled away.
• The Evade Traps skill will prevent you from being caught in any visible trap, but a hidden trap can still catch you by surprise.
  • Pits and spiked pits can be filled in with boulders or liquids. Objects in the pit will be buried or submerged, but will still be there if later uncovered. (q.v. Earth Hammer)
  • Once you're in a pit or spiked pit, you can try to climb out. Each try has a 50% chance to get out, otherwise you will "slip back" to the bottom. If you can jump or fly, that will always get you out in one turn.
  • If you've moved onto a pit or spiked pit without falling in (or have just climbed out), you can climb down into the pit. This will let you see, and retrieve, any objects which may be down there. (Mostly loot from unwary monsters.)
• Holes can be created with a Wand of Digging, or by using the Dig spell to knock the bottom out of a pit.
  • Holes cannot be plugged with boulders, or anything else.
  • You (and some monsters) can use holes to escape, or if you can't get to the stairs for whatever reason.

Liquids

The three liquid tiles are Water, Acid, and Lava. All offer the hazard of drowning, plus their own specific dangers.

Water: When on a water tile, you have a 50% chance each turn of sinking. Water does no damage aside from drowning, and if you are Aflame, swimming will put out the flames. It does not destroy items, but extinguishes Flaming Swords, Flaming Arrows, and Torches.

Acid: When on an acid tile, you have a 50% chance each turn of sinking. On or under the surface, you will take 4d3+9 acid damage per turn. Flying creatures can fly over acid without harm. Acid can dissolve soluble items.

Lava: When on a lava tile, you have only a 10% chance each turn of sinking into the lava. However, you will not only take 3d3+6 fire damage each turn, but be set aflame for 1d4+2 turns. (This will cause 1d6 fire damage each turn). This applies even if you are flying! Lava can burn flammable items, and can also set afire Long Swords, Arrows, and Clubs. Note that the Aflame intrinsic will not be extended until it expires. If you are still on or in the lava, you will of course be set aflame again.

• In all cases, if you sink into the liquid, you will drown and take 2d5 suffocation damage each turn. Being breathless will prevent drowning damage, as will Physical Immunity. You can also try to climb to the surface -- the chance of failing to do so ("You flounder...") is the same as the chance of sinking in the first place.
• The Walk on Water intrinsic will prevent sinking (and allow you to dive in or climb out at will), but will not protect you from fire or acid damage.
• If you are submerged when you try to move to a non-liquid tile, you will automatically try to climb to the surface first.
• Each turn you are submerged, one of your equipment slots is chosen at random. If you have an item there, and it can be affected by the liquid, it will be destroyed (or in a few cases, transformed).
• Fire Resistance or Acid Resistance will protect you from being burned or dissolved respectively, but not from drowning, and will not protect your equipment.
• In all cases, any damage or item destruction happens on heartbeat turns only.
• Items submerged in any liquid will be visible, and reachable, only if you are also submerged.
• Dropping empty bottles into any liquid will fill them, with water, Greek fire, or acid as appropriate. This makes liquid tiles important resources! Note that you will need to see the new potions (say, by going in after them) before you can Fetch them!
• Stashing items in a pool can keep them away from monsters.

Vapors

A number of effects can produce smoke, steam, acid smoke, or poison smoke. These are not tiles in their own right, but pass over other tiles, affecting any creature which passes through them (or vice versa). They will move around the dungeon (1 in 3 chance each turn), and occasionally disappear (according to type, as below). If there is a wind, the smoke will move in that direction.

Type	Chance to Vanish	Effects if breathed
Smoke	1 in 5	chokes for 1d2 damage, 10% chance of blinding for 2d3 turns
Steam	1 in 30	scalds for 2d4 damage (this is not fire damage)
Poison Smoke	1 in 5	chokes for 1d2 damage, 50% chance for 2 turns of Harshly Poisoned
Acid Smoke	1 in 5	burns for 3d4 acid damage

• Potion splashes or other effects can convert smoke or steam into acid or poison smoke.
• The passage of an Air Elemental will disperse any sort of vapor.
• Damage is taken on heartbeat turns only. Being breathless will protect against all smoke. Physical Immunity will protect against all but acid smoke.

Conversions

• Pushing, rolling, or otherwise moving, a boulder onto a pit, spiked pit, or any liquid square, will fill it, converting it to a floor (corridor) tile. If there was a Warhammer in the pit, it will be transformed into a (buried) Earth Hammer.
• Various cold-based spells and effects (including the passage of a Living Frost) will freeze water into ice, and lava into ordinary floor. (Acid does not freeze.) Any of these will also put out a forest fire. Freezing a water square will also transform any submerged Maces into buried Ice Maces.
• Similarly, various fire-based spells and effects, including the passage of a Fire Elemental, will melt ice into water, set forest tiles afire, and boil away water or acid. Boiling water or acid will leave behind a Pit and a square of steam or acid smoke respectively.
• The Down Pour spell will convert lava to stone, and put out forest fires. It will also fill a pit or spiked pit, converting it to a water tile.
• The Acid Pool spell will convert almost any tile to a pool of acid.
• The Sunfire spell converts almost all tiles within its range into lava.
• If a pit or spiked pit is next to a water, acid, or lava tile, the liquid will flow to fill the pit. This means that if only part of a section of water or acid is boiled away, the remainder will rapidly refill the resulting pits.
• Adjacent squares can otherwise affect each other, especially lava next to almost anything else; this is seen especially on Quizar's level.
• If you are submerged or in a pit when your square gets frozen or filled, you will be trapped, and will need to dig or teleport your way out before you suffocate (same as drowning, above).