Let it end in hellfire!

Clear

Henzell says...

1. A trap that drops you 1-3 floors and then disappears. Formicids have the ability to shaft themselves.
2. Hidden shafts won't spawn a floor above the bottom of the following branches: all rune ends, Elf, Zot, Crypt; long shafts won't lead into the bottom of those branches either. Shafts don't spawn on levels that don't have anything below them, like rune branch ends or Pan levels, and don't spawn in Tomb either.
3. Only one random shaft can spawn per branch: If you were shafted from D:3 to D:5, you cannot ever be shafted in D ever again. This only applies to exploration-trap shafts: the kind that you can see on the ground work like normal, in that you are never affected by them unless you want to be.

Information based on master branch and the great LearnDB.
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