Assuming you have set up instance variables for each individual object called Damage, this is why Families are powerful because you have a 'Family Instance variable'. That is what you're referencing there but you haven't used it. Create a family instance variable called Damage then every enemy will have it (you don't need to add the variable individually to each member of Enemies). You can only reference Enemies.Damage if it's setup for family, otherwise you need to reference individual enemies, EnemyA.Damage, EnemyB.Damage. Better to group in a family, which is what you're trying to do I can see but didn't quite get there yet