This server-side mod adds a brand-new, fully configurable Double Jump enchantment for boots.

Enchantment on boots

Please report any bugs, errors, or feature suggestions on Discord: https://discord.gg/4XUPywnEyE

Install on the server. Client installation is optional (vanilla clients can join and use it seamlessly). Singleplayer note: Works perfectly in singleplayer. Just install it normally in your mods folder.

Features

100% Server-Side: Works seamlessly on Forge (1.20.1), NeoForge (1.21.1), and Fabric (1.20.1, 1.21.1, 1.21.11 via loader 0.18.4).
Intuitive Mechanics: Use your double jump once while in the air. The ability resets the moment your feet touch the ground.
Customizable Power: You decide exactly how many enchantment levels exist and how strong the jump boost is for each level.
Vanilla-style Anvil Upgrades: Players can combine enchantment books to level them up, just like regular Minecraft enchantments.
Modpack Ready: Ships with 10 built-in language translations out of the box.
Treasure Chest Loot Support: Double Jump enchanted books can spawn in vanilla treasure chests (fully configurable, can be disabled).
Optional Treasure-Only Mode: You can make Double Jump a treasure-only enchantment via config (disabled by default for backward compatibility).

Configuration Made Easy

You have full control over how the mod behaves. You can find the config file here:

Forge / NeoForge: <server>/config/doublejumpenchant-server.toml
Fabric: <server>/config/doublejumpenchant-server.json

Config Options:

levelBoosts — A list of jump strengths. The number of values you put here automatically determines how many levels the enchantment has!
allowBookUpgrades — Turn on/off the ability to combine books on an anvil.
anvilUpgradeExperienceCost — Set the exact XP level cost for combining books.
treasureBooksEnabled — Enable/disable chest generation for Double Jump books.
treasureBookChance — Global chance to add the Double Jump loot pool.
treasureBookMinRolls — Minimum rolls for that loot pool.
treasureBookMaxRolls — Maximum rolls for that loot pool.
treasureBookLevelWeights — Per-level weights (e.g. [6, 3, 1]).
treasureBookLootTables — List of loot tables where books may appear.
treasureOnlyEnchantment — If true, Double Jump is treated as treasure-only (not obtainable from the enchanting table).

Default Setup: Out of the box, the mod is balanced with 3 tiers and anvil upgrades enabled:

levelBoosts = [0.38, 0.47, 0.54]
allowBookUpgrades = true
anvilUpgradeExperienceCost = 8
treasureBooksEnabled = true
treasureBookChance = 0.12
treasureBookMinRolls = 1
treasureBookMaxRolls = 1
treasureBookLevelWeights = [6, 3, 1]
treasureOnlyEnchantment = false

How Anvil Upgrades Work

If you have allowBookUpgrades set to true, players can combine books of the same tier to reach the next level:

Double Jump I + Double Jump I ➔ Double Jump II
Double Jump II + Double Jump II ➔ Double Jump III (Players can only craft up to the highest level you've defined in your config).

For Modpack Creators

Under the hood, the enchantment is registered with support for up to 10 levels. This means you can easily add or remove levels via the config without ever needing to rebuild the .jar file.
In normal survival gameplay, the mod strictly follows the levels defined in your levelBoosts config.
If an admin uses a command to give a player a level higher than your config allows (e.g., Level 5 when only 3 are configured), the jump strength will safely cap out at your highest configured value.

Double Jump Enchant