Bonk's XP Multiplier

XP Multiplier

XP Multiplier does one thing and does it properly: it changes how much experience you earn. One number for mob kills, another for everything else — enchanting, mending and repairs stop being the bottleneck, or become a real one if you turn the rates down instead.

Everything runs server-side. Players join with a vanilla client and get the full effect: no client mod, no resource pack, no config sync.

Features

🎚️ Two rates, or one per mob

Mob kills and the rest of the game are separate settings, so you can quadruple mob experience without touching ore or furnace output. Then override any mob that deserves its own rate.

"multiplier": 2.0,
"other_multiplier": 1.0,
"per_mob": {
  "minecraft:enderman": 4.0,
  "minecraft:blaze": 3.0
}

🌍 Every source, not just mobs

other_multiplier covers ores, furnaces and smokers, fishing, breeding, villager and wandering trader deals, grindstones and thrown bottles o' enchanting — because they all award experience through the same place in the game, and none of them was left out by accident.

🎲 Fractions actually work

A rate of 1.5 isn't rounded away. The whole part is guaranteed and the remainder is a chance, so 7 experience at 1.5× pays out 10 points half the time and 11 the other half. Over many awards that averages to exactly 1.5× — any single award is a coin flip rather than a promise, which is the honest cost of allowing fractions at all.

📉 Or make it harder

Rates go down to 0.0, not just up. Halve every award for a slower server, or set mob experience to 0.0 and force players to earn levels from ores and trades instead. The same fraction handling applies, so 0.5 is a genuine coin flip per award rather than a rounding rule.

🚫 Blacklist and boss safety

The ender dragon and the wither are excluded by default, because a single kill worth thousands of points is exactly the wrong thing to multiply. Delete them from the list if you disagree — nothing is hardcoded.

The dragon is a genuine special case: it hands out its experience during the death animation instead of the usual drop, which is how it slips past most mods of this kind. It is handled explicitly here, so blacklisting it actually works and a per-mob rate for it actually applies.

👤 Player kills only, or everything

By default only kills credited to a player are multiplied. Vanilla already withholds mob experience unless a player damaged the mob recently, so this mainly decides what happens to the finishing blow — turn require_player_kill off and a mob a wolf finished for you still counts.

🛡️ Never duplicates a player's levels

The experience a player drops on death is a slice of what they had already earned, not a fresh reward. Players are excluded unconditionally — there is no config option that can turn dying into a way to print levels.

Commands

Installation

1. Install Fabric Loader and Fabric API
2. Drop the jar into your mods folder
3. Start the server — config/xpmultiplier.json generates on first launch

Required on the server only. Installing it client-side in singleplayer works just as well (singleplayer runs an internal server).

Configuration

The file lives at config/xpmultiplier.json and is written with a comment header explaining every option.

{
  "enabled": true,
  "multiplier": 2.0,
  "other_multiplier": 2.0,
  "require_player_kill": true,
  "per_mob": {
    "minecraft:enderman": 4.0
  },
  "blacklist": [
    "minecraft:ender_dragon",
    "minecraft:wither"
  ]
}

Reading is lenient, so you can keep your own // notes in the file — they are dropped the next time the file is rewritten.

Compatibility

• Minecraft: 1.21 – 1.21.1, 1.21.9 – 1.21.11, and 26.2
• Loader: Fabric
• Dependencies: Fabric API
• Side: server-side (clients need nothing)
• Works with modded mobs: rates are keyed by entity id, so any mod's mob can be given its own rate or excluded
• Modded experience sources are multiplied too, as long as they award experience the normal way — they land under other_multiplier

Support

Everything I make is free and MIT-licensed. If it saved you some time, you can buy me a coffee:

☕ ko-fi.com/bonkmods