I set this up in a kind of longwinded way, it can probably be cut down shorter. When two objects 'fight' or I assume collide or overlap, you can pick the nth instance of the overlap using system compare. In the overlap, one sprite will be instance 0, the other will be instance 1. You can compare that the instance variable rank for instance 0 is less than the variable rank for instance 1 and if so set instance 0 to destroy or 'lose', then put else set instance 1 to lose. This might be useful when doing these kind of 1 on 1 battles, it's Pick nth instance in system compare.