Shaft

Version 0.17: This article may not be up to date for the latest stable release of Crawl.

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. 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.
• Invisible shafts (like other traps) can be detected by increasing one's XL and/or worshipping Ashenzari.
• Note that flying will not protect you from shafts, much like other traps.

Monsters can 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.

Formicids have an innate ability to create shafts at their feet, which they immediately use to send themselves several floors lower.

Shafts will never appear on the final level of a branch or in single floor branches, nor do they appear in the Abyss, Hell, Pandemonium, or Ziggurats.

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 well-prepared characters. 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.

You can lure dangerous unsuspecting monsters over shafts to do away with them. This also works for flying monsters, who are "sucked into the shaft". Keep in mind that you will likely encounter them again on a lower level.

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