In a chessboxing fight two opponents play alternating rounds of chess
and boxing. The contest starts with a round of chess, followed by a
boxing round, followed by another round of chess and so on. In every
round of chess the FIDE rules for a 'Blitz game' apply, in every boxing
round the AIBA rules apply with the following extensions and
modifications:
In a contest there shall be 11 rounds, 6 rounds of chess, 5 rounds of
boxing. A round of chess takes 4 minutes. Each competitor has 12
minutes on the chess timer. As soon as the time runs out the game is
over.
A round of boxing takes 2 minutes. Between rounds there is a 1 minute
pause, during which competitors change their gear.
The contest is decided by: checkmate (chess round), exceeding the time
limit (chess round), retirement of an opponent (chess or boxing round),
KO (boxing round), or referee decision (boxing round). If the chess
game ends in a stalement, the opponent with the higher score in boxing
wins. If there is an equal score, the opponent with the black pieces
wins.
For more detailed information please download the rules.
*Taken from The World Chess Boxing Organisation.*