Keys

This also includes very unkeylike items that fulfil the role of a key.

These are extremely commonly single use fits anywhere keys. On rare occasions you get keys that fit to only specific locks, and in even rarer cases you get keys that fit several related locks (e.g. all doors of the same house). Alternatively these are single use fits only extremely specific thing (e.g. wire cutter that opens a path only at a very specific spot of a fence).

Related:
* Doors
* Containers
* Keycodes
* Lockpicking - used to bybass the need for a key.