You can see the rules [here](https://www.chessvariants.com/crossover.dir/gess.html). Note that when a piece's move causes it to overlap stones, any stones covered by the **footprint** get removed, not just those covered by one of the piece's stones. It is not legal to make a move that leaves you without a ring. It's possible for a player to have more than one ring. A player doesn't lose until they have no remaining rings. Locations on the board will be specified using columns labeled a-t and rows labeled 1-20, with row 1 being the Black side and row 20 the White side. The actual board is only columns b-s and rows 2-19. The center of the piece being moved must stay within those boundaries. An edge of the piece may go into columns a or t, or rows 1 or 20, but any pieces there are removed at the end of the move. Black goes first. There's an online implementation [here](https://gess.h3mm3.com/) you can try, but it's not 100% consistent with the rules. In the case of any discrepancy between the online game and the rules, you should comply with the rules (you can also ask us for clarification of course). One example is that the online game lets you make moves that leave you without a ring, which isn't allowed (if a player wants to end the game, they can just resign). Another example is that the online game lets you choose a piece whose center is off the board (in columns a or t, or in rows 1 or 20), which isn't allowed.