Rive is a territory game. When the board is filled, the player with the most checkers wins. Groups are comprised of both colors of checkers. The placement rule is as follows: The largest group your newly placed stone connects to must be as small as possible.

Capturing placements: When you place a stone that connects to two or three groups, you must remove stones from the newly formed group, of either or both colors, to bring the group size down to one stone larger than the largest of the groups that was so combined. Selecting stones for removal from the newly formed group must be done in a way that does not split the group into two or more smaller groups.

Multiple placements per turn: When you make a capture, you must add another stone to the board while it's still your turn. And you must continue to add stones during your turn until you make a non-capturing placement.