|A hole in the ground, leading to a dungeon level one or more floors deeper.|
Shafts are traps that can be found on almost any floor in the Dungeon. Although they deal no damage, these pitfalls can send creatures down several floors. Each shaft can only activate once, as they crumble after a creature has passed through them. Flight has no effect on shafts.
A shaft resembles a gaping hole in the floor and functions similar to an escape hatch: the player can safely walk over one, but if they jump down (with the > key), they will descend 1-3 floors. Unlike stairs or escape hatches, moving through shafts occurs instantly, preventing monsters from following you or getting in free hits against you. Monsters can fall through shafts as well, dumping them onto a lower floor much like the player. Intelligent monsters are more likely to avoid shafts.
Formicids have an innate ability to create shafts at their feet, which they can use to send themselves deeper. This takes a few turns, but will take them out of immediate danger (though their landing spot is not guaranteed to be safe).
Shafts will never appear on the final level of a branch or in single-floor branches, nor do they appear in the Tomb, Abyss, Hell, Pandemonium, or Ziggurats.
Shafts may be triggered randomly by a sourceless malevolence whenever you uncover new tiles. They forcefully send you down 1-3 floors. Exploration shafts are held under the following conditions:
- Worshippers of Ashenzari at 4* and those wearing the mountain boots are immune.
- They don't trigger wherever floor shafts are unable to spawn (Tomb, Abyss, Hell, Pandemonium, or Ziggurats).
- Except in the Dungeon / Depths, Lair, and Orc, an exploration shaft can not take you down to a branch's final floor.
- A shaft needs a valid floor below to drop you to. This excludes all final floors, and most second-to-last floors (barring the above branches).
- Exploration shafts may only trigger once per branch.
Also, in the Dungeon, an exploration shaft will always try to place you in an area without monsters.
Shafts can be helpful or deadly, depending on the situation. Exploration shafts 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 always the danger you may land in a worse situation, but it may be worth the risk.
You can lure dangerous monsters over shafts to do away with them. Keep in mind that you will likely encounter them again on a lower level, but hopefully you will have gained enough experience to be able to fight them effectively by the time you get there.
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.
- Prior to 0.29, exploration shafts in the Dungeon did not try and place you in a safe location.
- Prior to 0.28, players could be exploration shafted more than once per branch.
- Prior to 0.26, followers of Nemelex could create shafts using the Shaft card.
- Prior to 0.24, player ghosts were immune to shafts.
- Prior to 0.19, items dropped on a shaft could fall through when the shaft collapsed.
- Prior to 0.16, flying creatures were immune to shafts. Also, the chance to escape a shaft was affected by the total (body + equipment) weight for monsters and players.