Jumping Multiplies Everything - Jubz

Made this datapack for a video, and people in the comments wanted to play it too, so here it is :)

Every time you jump, everything around you gets copied. Jump next to a chicken and now there are two chickens. Jump again and there are four, and it keeps going from there.

It works on mobs of every kind, dropped items, armor stands, boats, item frames, paintings, arrows, TNT, and more. It doesn't multiply the items in your inventory.

Made for Minecraft Java 1.21 and 1.21.1. I'm not 100% sure it works on other 1.21 versions.

Customization

You control how far the duplication reaches and how much of it happens. Both are changed by typing a command in chat:

1. Radius

/function jumping_multiplies:config/radius {value:25}

Default: 10 blocks. This is how far around you the pack looks when you jump. Anything within that distance gets copied.

2. Limit

/function jumping_multiplies:config/limit {value:100}

Default: 40.

The limit is per kind of thing, not a total. With the default of 40, one jump can give you 40 new chickens and 40 new cows and 40 new dropped items and 40 new zombies, all from the same jump. It's a cap on each type separately, not a cap on the jump.

It exists so that one jump doesn't try to copy hundreds of things at once and freeze the game. Lower it if things are getting laggy. Raise it if that's the point. Minimum is 1.

3. Checking and resetting

Prints your current radius and limit in chat:

/function jumping_multiplies:config/show

Puts both back to 10 and 40:

/function jumping_multiplies:config/reset

Installing

1. Open your world folder: Singleplayer → click your world → Edit → Open World Folder.
2. Go into the datapacks folder.
3. Drop the zip in. Don't unzip it.
4. Load the world, or type /reload if you're already in it.
5. You'll see "[Jump Multiply] Datapack loaded and working." in chat.