Thanks. Do you have any link to a specific tutorial? Where should I search for on youtube?
So the sprites inside the family have to be specified? I learned that you could pick an instance from a family, have seen some examples where people could pick an instance like that without specifying the independent sprites in the family
You can pick whichever sprite you want. But when you raise event 1 you need to specify which sprite that should be affected. Now you send it to the family, which means all sprites in the family will get that position.
So use some variable/name/index etc to specify which sprite/puzzle piece that you want to change position for, this reference should be passed in the message as well of course.
You must always remember that the sender and the receiver is different persons, which have no idea what the other one did, the only information you get is the data in the message.