My current project has a Bullet object, which gets destroyed if it collides with another bullet (so far so good). What I want is to check when 3 bullets collide and make something special happen (like a big explosion). So far I haven't found a way that doesn't involve having a collision count variable that resets after a short amount of time (say, dt) and checking if it reaches a certain value. Somehow I don't think that's a very good solution, given that it's not impossible for 2 different pairs of bullets to collide at the same time, which is not what I want to check for.
PS: I also tried comparing Bullet.PickedCount to 3 on the "On Collision" event, but it didn't work. When 3 bullets collide, all of them get destroyed, so I'm guessing that the engine treats the triple collision as 3 separate "On Collision" events