I am pretty sure that in previous versions, “Collision” did not work with the same object type on the left and right side ( “Object1 is in collision with Object1” would not detect collision).
It now works ! Which will probably make things much easier. Is it new ? Is it something that I had missed ?
I see what you’re trying to do, but if “Object1 is in collision with Object 1”, it just does nothing because only Object1 exists, but still, I’m interested to know on how you got that to work, because I really felt curious.
Well, it does. “Object1” in an object type, not an instance.
For example, I am planting seeds (instancing seeds where I click the mouse). If two instances of seed collide, they both die :
Condition : Seed is in collision with Seed - Action : Delete Seed
The “Seed” in the action being every instances of Seed which collide with another instance of Seed.
It works, and I am pleased 
But I am pretty sure that when I was trying this last August, it didn’t work. I am wondering if it has always been the case (and thus my recollection is wrong), or it if is new.
Oh, now I know what you’re talking about. You’re duplicating both sprites so that when the same object types collide, they all die.
I think you could always do it for simple stuffs such as deleting the object, but it won’t work for more complex actions like, “Add a force to move toward an object” if both of the objects are the cheese. You will still need another object to act as the collider. (At least based on my experience)
@Digitalstickmans ok thanks ! I get it.