in my opinion the tool repairing system is a little week, heres some ways i think it could be improved.
1. have a special block just for repairing tools, like a smithing station, something like that.
2. instead of combining two items, i think you should be able to put more of an item into your tool. for example, if you want to repair your diamond pick that only has 1/3 of its life in it. you could place your pickaxe in the smithing station, and two diamonds to put it back up to full damage.
3. be able to repair enchanted items. as it is currently, it is impossible to repair enchanted items, and if you try, it will remove the enchantment. lets say you did a level 50 enchantment on a diamond pick, and you got efficiency IV, Unbreaking III. if the pick is at 1/3 of its life, you would have to put two diamonds, and around 33 levels of xp, (bieng 2/3 of 50) and then you could have a fully repaired and still enchanted diamond pick.
with all of these, you will still have to use your diamonds to repair them, but without having to try 4 or 5 times at enchanting a level 50 pick to get a new one. you can just use your xp to repair the enchantment.
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