All the normal rules of chess apply except for the possibility of evolution through promotion capturing. Pieces are seen as a combination of their abilities: the ability to move like a Knight, Bishop or Rook. Whenever a piece, not a pawn, other than the King captures another piece it adds any additional powers that piece had into its DNA and promotes to a hybrid piece. For example: a Rook that captures a Bishop gains the ability to move diagonally and evolves into a Queen.
 
Simple pieces are the Knight, Bishop and Rook, compound pieces are the Cardinal [Bishop+Knight], Marshall [Rook+Knight], Queen [Rook+Bishop] and Amazon [Rook+Bishop+Knight]. Since the Amazon possesses all three powers, any piece that captures an Amazon becomes an Amazon. All other captures that cause evolution are listed below.
 
Knight + Bishop/Cardinal = Cardinal
Knight + Rook/Marshall = Marshall
Knight + Queen = Amazon
Bishop + Knight/Cardinal = Cardinal
Bishop + Rook/Queen = Queen
Bishop + Marshall = Amazon
Rook + Knight/Marshall = Marshall
Rook + Bishop/Queen = Queen
Rook + Cardinal = Amazon
Cardinal + Rook/Marshall/Queen = Amazon
Marshall + Bishop/Cardinal/Queen = Amazon
Queen + Knight/Cardinal/Marshall = Amazon
 
Pawns are seen as underdeveloped species which can adapt or evolve through promotion into any of the simple pieces: Knight, Bishop or Rook. Hybridization can only be achieved through promotion capturing, there are no shortcuts in evolution.
 
This game is young and may see minor changes in the future.