that depends on what each has at their dispostal. if mario has 1 life left and is tiny, and master cheif has a scorpion (tank) then master cheif wins. if mario is big, can shoot fire balls out of his nose (that seriously is what happens in the original super mario bros.) and has like 10 hrs. of invincibility form those star things, and master cheifs sheild is gone and he has no ammo, then mario wins. if both are at their best... chuck norris wins.