Variant where White cannot lose?

Question

I was pondering an asymmetrical variant where White's king is just a regular piece that moves like a normal king, but can be captured without consequence (and hence check for White does not exist). The game would consist of Black attempting to avoid being checkmated for X moves. (X might be 30?)

Is there any such known variant?

Answer 1

A similar variant absouletly exists and is called Mate in X chess. Generally it is used as a training tool or for when you have 2 opponents with a vast disparity in rating. For example, the goal may be to checkmate black in 20 moves, otherwise you lose. However white can lose the traditional way, but that is generally rare.