Typically in chess, the checkmate rule is explained as a early resignation because you are about to be mated one way or another. In bullet over the board chess, the game is even played with the 'take the king rule' when your opponent makes an illegal move that would allow you to do so. It gets fuzzier in 4 player chess, and it can be confusing to new players about who gets the credit for a mate when another player is the one doing the mating. Clearly there is some debate here https://www.chess.com/clubs/forum/view/king-capture-instead-of-checkmate-rules-discussion. Still, assuming that you will always capture a king when you can, there is still some argument to be made. Plus stalemate is funny. But in teams, not only is it more confusing, but it is 'wrong' in that the checkmate rule is not the same as the checkmate rule. https://imgur.com/fEUUlwE For example, here blue can capture the yellow pawn and win immediately. But if yellow had a move, they could moved their king down towards the blue queen, and after green does some move, red can capture the blue queen with their rook, so yellow will be saved. The whole logic gets even more confusing with the rule that you only get checkmated when it's your turn to move - so positions that look like checkmate may not be, and your teammate can save you. But as the position above shows, it's only some of the time... considering how many mate threats happen in 2v2, it would be nice to be able to calculate them with a bit more ease. Well, here is a puzzle that only works with the current ruleset. Using the fact that the game isn't played to king capture, there's a way to get a mate very quickly. https://imgur.com/RZvygUz Edit: Seems my images were removed when trying to post them. I have replaced them with links to images, as I can't find a way to display them inline.