Bughouse
Four players, two boards, captured pieces flow between partners — chess as a team sport, played at blitz speed, with shouting allowed.
Bughouse is the most physically and mentally noisy variant in the chess family. Four players sit at two boards arranged side by side. Two partners play together against the other two: one plays white on one board, the other plays black on the other. When a player captures a piece, it does not go into the captured-piece tray — it goes to their partner, who can then drop that piece onto an empty square of their own board, anywhere on the board, as their move.
The chess that results is fast, tactical, and constantly interactive between partners. The Russian-language chess community calls it шведки (shvedki — literally “Swedish [game]”); the English-language name is bughouse; in some other traditions it is tandem chess or Siamese chess.
The rules
Four players, two boards. Player 1 plays White at board A; their partner Player 2 plays Black at board B. The opponents are Player 3 (Black, board A) and Player 4 (White, board B). Each board uses standard chess rules, played at a fast time control (typically 3+0 or 5+0 blitz).
When a player captures an enemy piece, that piece is passed to their partner. The partner can now drop that piece, on their next move, onto any empty square of their board — instead of moving an existing piece. Pawns cannot be dropped on the first or eighth rank. Pieces dropped that deliver check or mate are legal. A piece dropped on the seventh or second rank can still promote on the next move.
The game ends when one of the two boards finishes: either by checkmate, stalemate, or time forfeit. Whichever team wins on either board wins the match. Draws on both boards are very rare. Most bughouse games are decided by one side delivering a mate while the partner is still playing.
Why it is different
Standard chess punishes passive defence; bughouse punishes any defence at all. A bishop on a long diagonal can be neutralised in one move if the opponent receives a knight from their partner and drops it in the way. A king’s-side attack can be reinforced indefinitely if pieces keep arriving. The classical maxim that material is more important than activity is exactly inverted: in bughouse, activity is more important than material, because material flows.
The result is a game played at blitz speed where the opening positions matter less than they ever could in classical chess, and where the combinations involve pieces that are not yet on the board. A bughouse player has to constantly forecast what their partner is about to capture and what they themselves are about to give the opponent’s partner. This two-board awareness, more than any individual move, is the variant’s defining skill.
Communication and strategy
Bughouse is the only chess variant where talking to your partner is not just allowed but essential. Standard partner conversations include “I need a knight on g4,” “Don’t trade your bishop yet,” “Hold off on the rook exchange — I need pawns,” and the classic emergency call “PLEASE GIVE ME SOMETHING.” The most successful pairs have developed signal systems and priority languages: in tournament play, the rule is usually that any verbal communication is allowed but only between partners and only at your own turn.
Strategic concepts in bughouse: piece flow (which captures benefit your team vs. the opponents), tempo management (your moves take time that your partner doesn’t get), and the standard middlegame ideas (king safety, piece coordination, central control) all apply, but the time horizons are shorter and the resource availability shifts constantly.
The name: Шведки
The Russian-language chess community calls bughouse шведки — pronounced shvédki — which translates approximately as “Swedish [game].” The etymology is uncertain. One common explanation is that the game was popular in Sweden in the early twentieth century and the name travelled to Russia from there. Another holds that the game was introduced to the Soviet Union by Swedish sailors in the 1920s, picking up the demonym in transit. Neither explanation is well-documented; the name has simply stuck.
In English the most common name has been bughouse (from American slang of the 1950s, meaning “crazy place”), with tandem chess and Siamese chess as alternatives. International tournaments tend to use bughouse; casual European players often use the local-language name. The game is the same.
Where to play
Lichess offers bughouse occasionally in special tournaments. Chess.com has built a permanent four-player chess section that includes bughouse-style games. The over-the-board scene is most active at weekend opens and informal club events.
The competitive bughouse scene is small but devoted. Top players include several grandmasters — Hikaru Nakamura is the most consistent elite-level bughouse player in the modern era — alongside specialists who play almost exclusively this variant. The World Bughouse Championship runs annually with an online qualifier; participation is open and welcoming to anyone willing to play with a partner.