Allows to notify objects that an event has happened. Also, allows to observe when an instance variable changes.
I thought this was going to be a great solution for being able to trigger enemies to have unique death and hurt events until I put it in and having 84 instances that don't do anything nor even use the behavior ACEs makes my behavior CPU use go up by 20%. I guess I'll have to just go back to using functions despite I don't like having to make a function for every single object type for this kind of thing.
Interesting issue, I should give it a look to see how to make the behavior stop doing all its calculations every tick or something.