ahaha moo)s(, why didnt u jus ask at WoS...anyway...yeh....depends...you gotta make the trigger like this sorta...
-make it so when the player kills a unit, it brings its death count back to zero...wel i guess it depends on the type of map it is...
-you can make it so when a computer kills a certain amount of units at a random location a trigger starts...then make the a triggger to bring it back down to zero. so it happens repeatedly