It doesn't even have to be that arbitrary. You've got an opponent with a defense against all your current weapons, but you can run faster than them, so you can escape but you still need to find something that can kill them. They need to find something that can make them faster so they can catch you, or take their chances by giving up the defense which is slowing them down.
There can still be strategy in it without leaving any easy way to cheat.
probably family friendly.
should make it.