Every Item is "wrapped by an ItemStack", isnt it? That means that values cannot be changed while ingame. For example, if I wanted to change the maximum durability of a Tool while ingame, it wouldn't work because every Item is defined and cannot be changed individually... 

 

In my case, I want to set the Attack Damage of a Weapon, depending on a capability value of the player who created it... But Minecraft would simply do something like this on creating an Item, wouldn't it?

 

new ItemStack(ModItems.EXAMPLE)

 

EXAMPLE would then be an instance of an Item, but this would have the same value for every ItemStack that is created. So this wont Work for me.

You really should dig through the Item class at some point.

    public int getMaxDamage(ItemStack stack)
    {
        return getMaxDamage();
    }

ItemStacks can store data beyond just what Item it represents, but also capabilities and NBT data, all of which is accessible in the above Item method.

Edited December 9, 20177 yr by Draco18s