I was wondering how, exactly, the Mending enchant worked – particularly when it comes to multiple items with the enchant. So let’s do some science!
The wiki, when I last looked at it, did not specify how multiple Mending items were handled. And I got into a YouTube comment discussion about it, so I decided to test.
The wiki was recently updated to clarify the behavior, and is correct. If more than one item with the Mending enchant is in an eligible slot, the XP is applied to one picked at random. If no repair is necessary, the XP goes to the XP bar.
There are six eligible slots – the four armor slots, the offhand (shield) slot, and in the hand.
The takeaway – if you want to focus repair on one item, you should remove any armor that has the Mending enchant.
Each XP orb is able to repair two durability points (per the wiki). I am not sure what happens if there is only one Mending item and it only needs one durability point to be completely repaired, and only one XP orb is picked up. Essentially, there is one half of an XP orb left over – is it lost, or does it go to the XP bar?
I have to design an experiment to test that next.