Corridor

Corridors, represented by # (or # if lit), are passageways connecting rooms in the Dungeons of Doom and Minetown. Not all corridors lead to rooms, and many have hidden sections (called a secret passage) which must be located by searching. Others may have boulders blocking your path. It is never impossible to progress further in the dungeon. If you come to a dead end, search all the walls until you find a secret passage. If a boulder is blocking your path, either destroy it (if you can) or drop everything you have so you can squeeze by the boulder and try to push it to a better location.

Corridors are usually single file and always unlit. Telepathy, Warning or Infravision are helpful when walking in corridors.

Gehennom and Sokoban also have passageways and single file routes. However these are the level itself, rather than connecting rooms.

With the exception of death drops and the occasional scroll of teleportation, there is no loot in corridors, but mercifully also no traps.

Strategy

Advantages

The advantages of a corridor is that they are usually single file so you are less likely to be overwhelmed with enemies by numbers alone. The single file space also lines up enemies for convenient disposal by wands, spells or ranged attacks.

If you are overwhelmed by a long column of enemies you can displace your pet; switching places with it for a few turns to recuperate.

Disadvantages

The disadvantages of a corridor is the darkness means you have difficulty locating enemies without Telepathy, Warning or Infravision. If you use an unidentified wand or potion, you will not identify it unless it is polymorph or a non-directional wand. These are bigger problems for those roles relying on ranged attacks. A light source helps you avoid cockatrices, but also helps enemies find you.

Traipsing around corridors looking for loot and the downstairs burns your nutrition. In the first five levels this can force you to charge headlong in search of a fight in order to find corpses to eat.

Tips

Cut corners to save time and get around faster. Corridors end when you find a door. If you are on an early level be sure it isn't a shop door before you kick it down. If the corridor ends and there is no door, chances are there is a secret door nearby.

Use a light source if you can spare it to avoid any awkward encounters. A light spell is particularly useful since it is permanent.

See if you can establish a circuit, a series of rooms and corridors you can cycle indefinitely to hold off and kill monsters which are as slow or slower but more powerful than you (by running in a circle you will recharge HP and Power over time). See hit and run.

Creation of Corridors

You can create corridors yourself with the aid of a pick axe, dwarvish mattock, dig spell, wand of digging or polymorphing into a rock mole or umber hulk. If you find large amounts of rocks, gems or gold in a corridor this is a sign it has been dug by a monster. Always think of the possibility of a bones file character.

In particular, without a means of teleportation you need this ability to reach a Vault, a 2x2 room filled with gold.