This is what makes it different – The Core Rules
1) Each piece is numbered. The pawns are P1, P2, P3 etc from left to right. Then there is R1, Kt1, B1, K, Q, B2, Kt2, R2. With the pieces numbered, one could use anything on top of the base as art. You can use traditional Staunton pieces. Or classic medieval pieces. But why not try Mechs or Klingons vs Federation or Jungle Animals.
2) Each piece has a corresponding statistic which will identify its combat play. You only have to worry about this sheet if you are going to fight.
3) In traditional chess, there is only one piece per square. In Fantasy Chess, you can have up to several pieces of your own color in a square. You can move your bishop into the pawn’s square. Then you can move the queen into that same square. A piece has to stop in an occupied square, except for the knight, which can land in an occupied square.
4) Instead of just taking the piece when you enter an enemy square as in traditional chess, you fight for the square (called a Combat Square). With the statistic sheet as reference, each piece in the square fights using dice to determine a successful hit, damage and kills. Several Combat Squares can be going on at once. Combat Squares are immune to check and pieces cannot move out of a Combat Square.
5) The king can get into traditional checkmate by not being able to get out of a capture position. Or he can actually get into combat (there are various ways this is achieved through Fantasy Chess movements.) If he is killed, that is also a checkmate.
6) Promotion is to pieces in the graveyard. If there are only pawns or no pieces in the graveyard, a temporary promotion to a super-pawn occurs which gives it special abilities, which he loses if he reenters the end row and promotes.