Kingmaker problem

A common problem in games with more than two problems: You have a player who cannot win, but who can choose which of the other players will win. If he can't be a King, he can at least be the man who makes the King.

Some games compensate by either making everybody play Solitaire or hiding who's winning. Some games don't, in order maximize backstabbing.

Examples include:

• Monopoly players offering their property for a song in a trade.
• Strategic games (like Risk or Civilization if you want to to /v/) players going kamakazi on one player to tie them up in order to aid another.
• Diplomacy, just Diplomacy.