I'm new to python and I'm trying to make a small text based game I've listed the amount of health the player has and when I try to edit the variable within a function it doesn't change the global variable and when I try to use the global command to define it as a global variable it says the parameter is already a global variable and return also doesn't work?

```
import random
health = 100
dHealth = 1000

def attack(dHealth):
    attack = random.randint(5,50)
    dHealth = dHealth - attack
    print("You dealth", attack,"damage, the dragon has", dHealth,"health left!")

attack(dHealth)
print(dHealth)    

```

I wanted the variable to go from 1000 to a number between 995 to 950