I saw a member asking about how families work. Here is a simple example (I like examples) how one sprite can interact with any family member. This is a powerful feature since you do not have to make a separate collisions for each brick in breakout, or rock in Asteroid.
The Capx is self explanatory, but you will see that all I did to make the family was:
* RIGHT click the Families in the Projects window of the Layout page and select Add Family.
* In the Edit object type window I SHIFT Clicked(to get both) Tank1 & Tank2, then the Add button and clicked OK
* I renamed my Family to Tanks
From there I accessed my Tanks family in the Event Sheet
(Beginner note: missile destroys itself outside of layout to save overhead.)
Thanks for looking