Thanks for your answer.
But I know how to generate a random value -_-"
I don't know how to generate it for each instance of the same object.
I have an enemy with many instance of him and i want that each of them have a different fire rate.
I can do something like :
Every random(1,4) seconde -> Create Object Bullet.
But this will choose a fire rate for ALL of the instance of my enemy and i don't want that. I want to generate one different for each of them.