Play begins with an empty 4x4x4 field. Each player in turn introduces their King to the field upon a vacant cell. Neither King may attack the other. Then each player in turn may do one of the following: introduce a new piece to the field or move a piece in the field.
 
All pieces are introduced on to vacant cells, and cannot give immediate check to the opponent King.
 
Pieces are a standard set of Chessmen and move according to their classic 3D movement. Pawns are replaced with Unicorns.
 
UNICORN slides triagonal.
ROOK slides orthogonal.
BISHOP slides diagonal.
KNIGHT leaps to the opposite cell of a 1x2x3 area.
QUEEN slides orthogonal, diagonal or triagonal.
KING steps orthogonal, diagonal or triagonal.
 
The game is won by check-mating the opponent King.
 
There is no form of promotion during this game.
 
 
This game is based upon several ideas by V. R. Parton for Chess-play on smaller fields.