The simplest way is to use the options in an Encounter trigger. Build your Encouter trigger, right-click on it, and select Properties. * In the Basic TAB, select "Continuous". * In the Advanced TAB, select "Encounter Respawns" * Set the "Respawn Time", "Number Of Times To Respawn", or select "Infinite Respawn". This will cause your encounters to respawn the creatures. Be sure to play around with the shape of the trigger. You can make the trigger the same size of your map if you want.