So, I have noticed that when trying to combine enchantments with Equipment/Books, occasionally, the enchantments will not be applied, simply because there are too many enchantments on an item.
For example, I might have 2 books. One with, say, Unbreaking, Silk Touch, and Mending, and another with Protection, Aqua Affinity, and Frost Walker. In this example, (I'm not sure if these sets of enchantments will combine – will test this later) they will drop off an enchantment due to the "cap" of enchantments on an item.
I know that some Enchantments make others redundant (I.e. Silk Touch and Fortune, or vice-versa), so they will not combine. Others simply overlap – like the same enchantment of different levels (Unbreaking 3 overwrites Unbreaking 2). And obviously, enchantments that cannot be applied to equipment will simply not be, like Aqua Affinity on a pair of boots. However, after several tests, I haven't been able to figure out how the enchantments are dropped when combining them, outside of these parameters.
Is there any way I can determine which enchantment I will lose when combining books? And will this affect Curses too (Curse of the Vanishing/Curse of Binding)?
Best Answer
Only the enchantments that are compatible with the item will apply, regardless of how many they are, however the costs may increase the more enchantments you apply, the better they are, and the more combinations you do. And, also as you said, certain enchantments won't stack, except by Creative Mode means. Examples are multiple type of Protection, Silk Touch and Fortune, etc.
Note that if there are conflicting enchantments, those on the item placed in the first slot of an Anvil will replace the ones of the other item's. Those on the item in the second slot will be erased.
See here a complete list of the enchantments, and where they can be applied, and how.