I have a custom item which i want to apply damage to when i click a custom block. The whole point to it is that after clicking a block, it takes one more damage until its damage is at 0 and must click another block for it to "refill" the damage before being used again. In the items constructor i set the max damage to 16. In the items use method, after all other logic is done, i call the items set damage method and set it as 1 lower than what it currently is. Also when i click on another certain block im calling the set damage method to the items max damage, as in the item gets fully repaired (without using anvils). In game this doesnt work, and no damage bar is shown on the item. I cannot post my code as im not home on my computer. So basically the question is how do i allow an item to lower its damage when clicked on a certain block, and how can the items damage "refill" after clicking another block. Or in better terms, how does minecraft handle item damage to items that are not considered tools?

Damage is incremental, not decremental. When the item's damage value equals the max damage value, that is displayed as '0/max' and the item breaks, but really it is 'max/max'. An undamaged item is '0/max', but displays the opposite.

 

Normally you use ItemStack#damageItem to damage an itemstack, not #setItemDamage.