Enchantment Calculator

The three numbers offered at the table are not a lapis-and-level price — they are the minimum enchanting level you need to unlock that slot. You still spend exactly 1, 2, or 3 lapis lazuli and that many experience levels no matter how strong the resulting enchantments are.

Treasure-only enchantments (Mending, Frost Walker, Curse of Binding, Curse of Vanishing, Soul Speed, Swift Sneak) never come from the table at all — the only vanilla sources are fishing, trading, loot chests, or the anvil.

The three offers are rerolled only when you either spend one of them or remove the item and place a different one (or a different item type) on the table. Swapping bookshelves around the table, or waiting, does not reroll anything by itself.

Each combine step on the anvil charges experience levels for three things added together: the target item’s own prior-work penalty, the sacrifice’s prior-work penalty, and the cost of whatever enchantments actually move across. An enchantment only costs levels if it is new to the target or upgrades an existing level on the target — an enchantment the target already has at an equal or higher level is free, since nothing changes.

The per-enchantment cost is final level × that enchantment’s anvil multiplier. Cheap combat/tool/armor enchantments (Sharpness, Protection, Efficiency, Fortune, Unbreaking, and most others) multiply by 1. A handful of stronger effects multiply by 2 (Mending, Infinity, Frost Walker, Flame, Luck of the Sea, Lure, Channeling), and the rarest multiply by 4 (Silk Touch, Thorns, Soul Speed, Swift Sneak, the curses, and the newer mace enchantments). If the source of the enchantment is an enchanted book rather than another tool/armor piece, every one of those multipliers is halved and rounded down (minimum 1) — this is why merging books onto a final item is cheaper than merging finished tools together.

The prior-work penalty itself doubles-and-adds-one every time an item goes through the anvil: 0 uses costs nothing extra, then 1, 3, 7, 15, 31, 63 levels for 1 through 6 prior uses (the formula is 2^n − 1). Whichever item comes out of a combine inherits max(target uses, sacrifice uses) + 1 as its new use-count, so repeatedly dumping enchantments onto the same item in the wrong order stacks this penalty fast. That is exactly why combine order matters when merging several books: pairing books together first (both still at 0 prior uses) and only touching the final tool/armor piece once tends to undercut an order that keeps re-anvilling the same item over and over. A total cost of 40 levels or more on any single step is rejected by Survival’s anvil as “Too Expensive!”, so 39 is the practical ceiling per combine.