At the Gallery we once invented a game in which we made up lateral thinking puzzles of this type as we went along. Someone starts with an implausible sort of scenario of this type and asks "what happened?" or "why?", but doesn't have any preconceived idea of what the answer might be. As the other players ask follow-up questions, the puzzle-setter makes random decisions until a sufficiently silly answer becomes clear.

We played this a couple of times. Highlights included:

Q. A man walks into a pub, buys a pint, and gives it to a dog. Why?

A. The man's best friend had bet him a pint that he could turn into a dog. The man accepted the bet, whereupon his friend turned into a dog, winning the bet.

Q. All the children in a school are lying in the playground with broken legs. After several attempts, an ambulance is called. What happened?

A. The teachers all had dyscalculia, which caused them to draw out the hopscotch layouts in the playground with all the numbers permuted into leg-breakingly difficult orders, and also made it hard for them to dial 999 correctly.

Q. There's a dark room. What happened?

A. Someone turned the lights out!

(Of course this is much more fun to play than to recount, and the other players' "wrong" guesses tend to be at least as good as the eventual official solution.)