Flux 4x4x4 Chess is played with a standard set of Chessmen, Unicorns replacing the Pawns. All pieces, excepting the King, can only exist on the field for a specific number of turns at a time. In this implementation that number is six.
 
Play begins with an empty field. Each player in turn introduces their King on an empty cell. Neither King may attack the other. Then each player may either introduce another piece or move a piece in the field.
 
All pieces are introduced on empty cells, without giving immediate check to the opponent King.
 
Pieces move accordingly:
 
UNICORN slides triagonal.
KNIGHT leaps to the opposite cell of a 1x2x3 area.
BISHOP slides diagonal.
ROOK slides orthogonal.
QUEEN slides orthogonal, diagonal or triagonal.
KING steps orthogonal, diagonal or triagonal.
 
Captured pieces are removed permanently from play. Pieces whose time has expired are removed after the player's turn, and remain the property of the player. Such removed pieces may be re-introduced by the player on subsequent turns.
 
The game is won by check-mating the opponent King. Of course, it is impossible to give check with a piece which will be immediately removed.
 
After introducing or moving a piece, click on the Change Turn icon located at the upper left corner of the board display to pass move to other player.