You can definitely do what you are trying to achieve, I'm just trying to get to the bottom of it lols. When you spawn the ship, of any type, you can set the shootspeed instance var to random(10,20) which would be a random value 10-20, and different for each ship. There are various ways to do this. You can do this with a family instance variable if it applies to every ship. If it's different speeds for different types you can say on Type A created, set instance var to random (10,20), Type B to random(60,80). This is how I would do it myself but there are many ways.