Complete ruleset for the Bughouse tournament

Generalities

1. Bughouse is played between two 2-player teams on two boards. Both teams have White on one board and Black on the other, both games start simultaneously.
   
2. The time control is of 5 minutes for each player for the whole game.
   
3. For each game, FIDE rules for 5-minutes blitz (rules of chess and appendix B & C) apply, if not mentioned otherwise in the following articles.
   
4. The first game to end decides of the match result; the remaining game is then stopped.
   
5. Both boards are placed near to each other and the clocks on the side, so that each player can see the time on both clocks.

Changes to the normal chess rules

6. Every piece taken can be given to the partner, who will place it in front of or near his board. These pieces are considered to be part of the partner's stock (they are of his piece colour).
   
7. Instead of a normal chess move, a player can drop a piece taken from his stock on any empty square (on his board), but with two restrictions:
   
   • he must not stay in check (obviously)
   • a pawn cannot be dropped on the first or last rank.
     
   If the drop leads to a checkmate, the player wins the game.
   
8. The pieces on a player's colour which are not on his board are considered to be potentially in the player's stock. Hence, unless all necessary pieces are on his board (very unlikely):
   
   • The player is not considered to be checkmated if he could parry the check with a piece potentially in his stock. Thus, a checkmate must almost always be given either with a "contact check", either with a knight check, or with a multiple check.
     
   • The player is not considered to be stalemated.
     
   Moreover, the FIDE rule #9.6 (allowing to claim a draw if checkmate is impossible to achieve against the poorest play) is cancelled.
   
9. A pawn moving to the last rank is promoted, but physically stays as a pawn; the player must orally point into which piece he wishes to promote - usually "queen" or "knight". If the pawn figuring the promoted piece is taken, it returns as a simple pawn in the partner's stock.

Progress of the match

10. Each player plays his own game: he is not, in any way, allowed to physically act on the other board or clock, for instance by pointing out a square or a piece with his finger.
    
11. However, all other forms of communication are allowed inside a team. A player may, for instance, tell a move to his partner.
    
12. As soon as one game is ended, each player of the game can stop playing and neutralize the clock. This puts an end to the match, even if after that his opponent finds a mate in one move. On the other hand, if both players neglect to neutralize the match, their game can go on. If a referee is present, he will by himself neutralize the match as soon as one game is ended.
    
13. If only one game has ended, it decides of the match result. On the other hand, if both games have ended, the following applies:
    
    • If both games are won by the same team, they win the match.
    • Otherwise the match is a draw.
      
14. Two games are considered to end simultaneously in the following case: a player takes a piece which allows his partner to mate immediately, but get himself mated immediately too. As dictated by the previous article, the match is a draw in this case.
    
15. A draw offer and the relevant agreement must be done by both players of the team, and it decides of the whole match.

Cases of contention

16. All players must have all pieces of their stocks well visible in front of their boards or just near it. More precisely:
    
    • If (by purpose or not) a player is hiding some of his stock's pieces, his opponent can press the clock and ask to see them.
      
    • If a piece has been stocked for some time elsewhere than in front or near the board where it could be dropped, it will then be completely removed from play. This is, for instance, the case when one player omits to pass a captured piece to his partner.
      
17. FIDE rules #4.3 and #4.4 (touch-move) do apply to a piece in the player's stock only after the latter deliberately made contact between the piece and an empty square (to drop it there). Of course, once the piece is dropped, the move cannot be taken back any more.
    
18. Like in FIDE rules, a move (except for a mating move) is considered to be finished only when the clock has been pressed. Consequently:
    
    • An illegal move leads to the loss of the game, but only if the clock has been pressed. Otherwise it can be taken back, but must be played with the same piece if this is possible.
      
    • A piece taken cannot be used by the partner before the clock is pressed.
      
19. A player can claim a draw after 4 repetitions of the same position counted in a loud voice, but only given that no piece has been dropped in between. On the other hand, he can claim a draw even if his opponent's stock has increased.
    
20. In case of contention, a team can neutralize the match and call for the referee. The players of the team must stop both clocks simultaneously.

The original text can be found in Fabrice Liardet's webpage.