Minecraft Anvil Prior Work Penalty & Tree Calculator
Never hit the dreaded "Too Expensive!" (40+ XP Limit) again. Compare linear sequential combining against binary tree pyramid merging for 7-enchantment God Boots & Swords.
๐ Gear & Book Setup
Penalty Formula: 2^Uses - 1 (0, 1, 3, 7, 15, 31 levels added per operation).
๐ณ Binary Pyramid vs Sequential Cost
๐ How the Prior Work Penalty Algorithm Works
Every time an item or enchanted book is combined on an anvil in Minecraft Survival mode, its internal RepairCost NBT tag increments. The XP penalty added to the next anvil operation follows 2^N - 1: 1 use adds +1 level, 2 uses add +3 levels, 3 uses add +7 levels, 4 uses add +15 levels, 5 uses add +31 levels, and 6 uses add +63 levels (instantly triggering the 40-level "Too Expensive!" Survival cap).
When you merge two items in a balanced Binary Tree, the new item inherits only max(LeftUses, RightUses) + 1. This allows you to pack 7 enchantments onto a single item while keeping the item's final anvil work count at just 3 uses (+7 levels penalty).