How does the “Preserve Trigger” action affect a trigger?
If a trigger does not have a “Preserve Trigger” action attached to it the trigger will fire only once when its conditions are met and then never fire again. A preserve trigger action will cause that trigger to execute every time the trigger’s conditions are met regardless of whether the trigger has already fired off one time, or a hundred times. The preserve trigger action is what is used to create the popular “madness” maps. These maps have an action that creates a unit type at a specific location and then a preserve trigger action so that the unit gets created over and over every two seconds when a trigger pass is made.
