By "prisoner" puzzles I mean those in which several different entities (conveniently perfect logicians) are locked in separate rooms and given various amounts of information. The goal is for one of them to be sure that a specific condition is true, usually through manipulating lightbulbs, switches, or other communication methods. (This tag would not be a subset or a superset of hat-guessing.)
This is a fairly common puzzle genre:
- Variation of 100 prisoners light problem
- 10 Prisoners, 10 Keys, and 7 Years
- The Circular Prison of Unknown Size
- A generalization of Tyler Seacrest's "Three voting prisoners" puzzle
- The Unknown Prison of Unknown Size
- Three mathematicians are forever in Prison
- The Two Switches
- Are there eighteen or twenty bars in my castle?
- Prison Pizza Party
- How long has the warden been the warden?
- How long has the warden been the warden? v2
I've added a few more examples of the genre, and am creating answers with suggestions for what this tag should be called, or for tag-not-needed. Please vote for the option you think should be taken.