This improv exercise was originally seen on Whose Line Is It Anyway? CH4, on British Television, but manipulated into an agile learning experience by myself and Geoff Watts during a collaboration day.
A buzzer or hooter
Two of the four player meet in an imaginary location (place of work etc) on stage. The only rule of the game is that they can only converse by asking each other questions in turn. If a player hesitates or makes a statement, they are buzzed out and replaced by one of the other players (how is standing behind them).
The game emphasises how hard it is to answer a question with another questions. As problem solving human beings, we are naturally drawn to providing an answer when given a question.
Geoff and I use this to position the ScrumMaster as someone who should encourage a Scrum team to solve their own problems instead of being seen as someone who will always have the answers.