What would happen if two people who had been given the power to never lose by a Genie played a game of chess together?

In this entirely hypothetical scenario, two people were both granted an ability that makes them unable to lose any game. These two people then go on to play a game of chess (or any 1v1 game) against each other. What would happen? I know there is literally no way of ever finding this out definitively but still. There’s gotta be like a math problem or similar hypothetical scenario that can give a satisfying answer.

And what if they played a game where it would be physically impossible for there to be a draw