Minecraft wiki entry for Before_1.8, associated text: The costs for enchanting with books expose more of the internals of the anvil system, but while this makes them more complex, they also include some major discounts compared to item combination. Naturally, repair costs do not apply. Normally, enchanted books only have one enchantment, but books with multiple enchantments can be produced by combining two books on an anvil. Such books will have their own prior-work penalty.