Bughouse Chess Rules

Bughouse or “transfer” chess is a 4-player game with 2 chess sets and 2 chess boards. The players are on 2 opposing teams of 2 players. The players on each time play opposite colors.

You can also play bughouse with only 2 players. You just need 2 sets, and you each play both boards at the same time. It’s a bit less fun though. (There is also a 2-player version with a single set called “crazyhouse”.)

The idea is that any piece that your teammate takes from their opponent are passed to you. And you are then allowed to do a “drop” move with that piece onto any vacant square!

Some of the rules and considerations:

  • First checkmate wins. Only one board needs to be checkmated. Sometimes it’s a bit unclear which board got checkmated first.
  • Resignations and draw agreements are allowed.
  • Can be played with or without clocks. Time forfeits (losing on time) can occur on either board if chess clocks are being used.
  • Dropped pieces cannot capture. They are only dropped onto empty squares.
  • Dropped pieces can check. It’s kind of the whole point of the game. Dropped pieces can go right up next to the enemy King. Dropped pawns can be deadly little checks.
  • Dropped pieces can block checks. Except for Knight checks and pawn checks, which cannot be blocked, making Knights and pawns much more valuable than usual in transfer chess games.
  • Talking is allowed. You can ask your opponent for pieces! Usually bughouse is a noisy, social game. However, there are official bughouse tournaments sometimes.

Playing bughouse chess with chess clocks creates some interesting situations. Sometimes one player will “sit” because they are about to be checkmated, but they hope their teammate will win on the other board before their clock runs out.

There are slightly different versions of bughouse rules, mostly in relation to the pawn’s specific rules:

  • Pawns can be dropped onto the 1st rank? Sometimes this is allowed. (They make good defenders.)
  • Pawns can be dropped onto the 8th rank? If allowed, they do not promote if they are “dropped” onto the 8th rank (they stay as pawns).
  • Pawn promotion is allowed in bughouse chess. Pawns dropped onto the 7th rank can also promote on the next move. Can promoted Queens be passed to your teammate, or do they revert back into pawns when captured? Sometimes pawn promotion is simply disallowed, as it needlessly complicated a game that is already very complicated!
  • “Sitting” is allowed or banned? With clocks, it can get interesting with time arithmetic. Without clocks, if one player is sitting, it gets a bit dull on the other board. Double sitting means a draw without clocks.

And there are a large variety of other sub-variants of bughouse with different rules. Most of these sub-variants impose additional restrictions on the “drop” moves. For example, it might be banned to drop a piece with check, making the game much slower (and, dare I say it, much duller…).