Bughouse
Bughouse is a chess variant played by four players in teams of two (partnerships) on separate boards. Each player competes against an opposing team member, with the goal of winning by checkmate or timeout.
In this variant, one partner plays Black, and the other plays White. Partners help each other by capturing enemy pieces which their partner may then place (drop) on an empty square on their turn.
Rules
When you capture an opponent's piece, it goes directly into your teammate's 'piece bank' for them to use at their discretion.
On any turn, instead of making a move, a player can 'drop' any piece from their 'piece bank' to any open square on the board.
Pawns may not be dropped on the 1st or 8th ranks.
A pawn that is placed on the 2nd rank may move two squares on its first move, as in standard chess.
Promoted pawns that are captured are returned to the piece bank as pawns, not as their promoted pieces. These are known as 'counterfeits.'
A bughouse game is over when a game on either board ends in checkmate, resignation, or timeout.
A check that could be blocked by a piece drop is not considered checkmate, even if the player doesn't have a piece in the bank.
📰 Check out this article for tips for beginners: 7 Doubles (Bughouse) Chess Tips For Beginners