What happens when a state-based action would cause two players to lose the game simultaneously in a multiplayer pod?

State-based actions are checked and applied simultaneously (CR 704.3). When multiple state-based actions apply at the same time — such as two players each having 0 or less life — all of them happen at once rather than sequentially.

In a multiplayer game, if two or more players would lose simultaneously due to state-based actions, all of those players lose at the same moment (CR 800.4). If all remaining players lose simultaneously this way, the game ends in a draw (CR 104.4b). If some players remain who did not lose, those players continue the game normally.

It is important to note that a player 'losing' in multiplayer means they leave the game (CR 800.4a). Their permanents are removed, spells and abilities they control are removed from the stack, and the game continues with the remaining players — unless no players remain, in which case it is a draw.

Concrete example: In a four-player Commander pod, Player A and Player B are each at 0 life at the same time state-based actions are checked. Both lose simultaneously and are removed from the game. Players C and D remain and continue playing. Neither A nor B 'wins' or 'loses to the other' — they both exit at the exact same moment.

In tournament play, a draw result for eliminated players is recorded as such, but the surviving players in the pod are unaffected and play on to determine a winner among themselves.