Nim

In choose-your-own-pile-nim, each player starts with an integral pile of beans of size n which they choose before the game starts. Depending on the group preference, n can be limited to a range {0,1,...,b}. Players will then take turns, and on each turn they must remove any natural number of beans from any other players pile, or their own. Do this by saying "I remove x beans from player y's pile". If the pile is empty, the player owning that pile must report so, and the individual who is attempting to take beans from that pile must choose a different pile to take beans from. Players keep track of the number of beans in their pile internally. If the pile is non-empty but more beans are removed than are currently in the pile, the player owning the pile says nothing and sets the number of beans in their pile to zero. The player who takes the last bean from the last non-empty pile wins the game.

Not to be confused with actual Nim, which is boring.