Shaft

A deep hole. Who knows where you might end up if you were to fall through it?

Shafts are traps that can be found on any floor in the Dungeon, though they are more common the lower you go. Although they deal no damage, these pitfalls can send adventurers, monsters, or items down several floors. They have no effect on anything that can fly or levitate. Shafts may be visible or invisible:

• A visible shaft resembles a gaping hole in the floor. In this state it is similar to an escape hatch: a character can safely walk over one, but if they jump down (with the > key), they will descend 1-3 floors.
• An invisible shaft detected using the Traps & Doors skill will turn into a visible one. Undetected, a character that walks over it may fall, though a low total body weight will improve your odds of avoiding it.
• Monsters may fall through shafts as well.

Shafts cannot be disarmed, but they always crumble after a player or monster falls through. Unlike stairs, moving through shafts occurs instantly, preventing monsters from following you or getting in free hits against you. Also, bear in mind that any item dropped on a shaft will fall through.

Strategy

Shafts can be helpful or deadly, depending on the situation. They can land you in very dangerous situations - dropping from D:6 to D:9 unexpectedly can mean death even for a reasonably well-prepared character. On the other hand, a known shaft is a powerful escape tool: unlike with staircases, monsters do not follow you through shafts or get any attacks in as you fall, very useful if you find yourself next to a powerful melee monster unexpectedly. Of course there is the danger you may land in a worse situation, but it may be worth the risk.

If you do fall through a shaft to a dangerous depth, a scroll of magic mapping will locate the stairways and escape hatches you can use to return to a safer level.