how do you make it so a projectile is fired, travels a certain distance, (maybe damages things) and leaves a trail of some sort of buff behind for a limited time. Example: Dota; Mercurial's shadow dagger leaves behind a slowing effect that works if you walk through it. Im trying to make an area like that, but every few seconds it has a chance to damage units in that area and display a special effect. thanks again for all the help in advance.