Coin Chess Variant Rules
Before first move coin is on square e4.
The coin must imitate the piece's move and must always go to an empty square. However it can jump units.
So its working like filter of standard chess moves.
When You cannot move using coin-rules You are coin-checkmated !
Stalemate is very rare, it happens when You are not in check and You have no moves in both : coin rules and standard chess rules.