These so called "tricky locks", are locks (often padlocks) with an unusual locking mechanism. The aim is to open the lock. If you have a key, it will not open the lock in the usual way. For some locks it may even be more difficult to close the padlock.
The lock-puzzles have a long history. Chinese jewelry boxes often contain padlocks with tricks and hidden drawers. An example of this kind of boxes is an integral part of the secret map in Knights of Shanghai movie. Clive Barker, a famous English writer and director, has written several horror stories based on the Lemarchand Box, which seems to be a puzzle-lock but actually, once resolved, it opens doors to hell. Underworld, Epic and Slaves of Hell; the movie "Hellraiser: There are no limits" was based on Slaves of Hell.
Other puzzle-locks derive from the need to invent safe locks in the Middle Ages.
Puzzle-locks are closely connected to the lock-boxes (read the article on Pandora's boxes).
Some examples are: