This is a mashup of chess and checkers. Set up a normal chess game but with 8 checkers on each side where the 8 pawns normally go.
The chess pieces move, attack, and capture as they normally do, including castling. The checkers move and capture (jump) as they normally do, diagonally. Checkers that reach the other side get kinged. If a checker can jump another checker or chess piece (or double or triple jump etc.), it must jump those pieces. If your checker must jump your opponent's piece(s), but you're also in check, you must get out of check instead of jumping with the checker.
The game is won by checkmating the opponent's king either by an attack from a chess piece just like in chess, or threat of being jumped by a checker piece that the king can't avoid.
I invented this game and the first time I tried playing it (about 15 years ago), I didn't think it would be any fun, but I was pleasantly surprised. It broke my brain as I mixed the two games in my head. I had to play chess while making sure my chess pieces weren't lined up in such a way that they could get double jumped! I also liked the fact that I could force moves on my opponent by placing pieces in position to be jumped by one of their checkers. Let me know if you find any rule collisions that I have missed.
-description from the designer
