In C-Cross, players take turns placing pawns in the grooved spaces of the board, and when someone has three pawns in a space, they remove their pawns and install one of their permanent C-bricks — but if an opposing pawn would be squashed by that brick, the active player must give that pawn a new home by swapping it for one of their pawns that lie elsewhere on the board. Yes, sometimes you must relinquish territory elsewhere to establish footing for yourself, another element familiar in abstract strategy games.
This minimal ruleset creates a delightfully troublesome game in which you can lose in almost any direction, especially when you make one terrible move, as I did in the video below...