
Radii
I don't know my version or loader
An easy to use datapack to limit your world size in an interesting way
Radii uses a system of concentric rings to apply buffs to hostile mobs and, after a certain point, directly damage players. Made in a way to feel nice and responsive, while still being light on performance. You can use the in-game function to configure the mod's settings, even disabling the level up mehcanics for only the border functionalities:
/function radii:config
Use cases
- For servers to encourage players to settle near spawn (or an area) whilst still providing a fun challenge and mechanic around it
- For players who prefer smaller/limited worlds and want a challenge while exploring
- ETC!
What does it do?
Radii has the following settings:
- Ring ammount: Total ammount of rings. Defaults to 10
- Ring size: Ammount of blocks between each ring. Defaults to 256
- Health and Damage factor: Percentage of total stat added for each level. Defaults to 50
- Center X and Z: Offset in blocks from (0, 0) that the script runs at. Defaults to 0
With these settings you would have:
- A world barrier that stops players from going further than ~2400 blocks in each dimension
- Mobs that level up based on distance to the origin, for example at the 9nth ring a zombie would have 100 health points
- On each dimension, the ring count starts from the last dimension's count, for example the first ring in the nether is the 10th ring and the first ring in the end is the 20th ring, making the difficulty scale with game progression seamlessly
- Players are notified whenever they enter a new ring, while leaving the last (9th as count starts from 0) ring they'll get a heavy debuff and suffer from magic damage
- Creative players are unaffected, allowing OPs in creative mode and modded creative dimensions to wander normally outside of the limits
Future plans
These things may or may not happen depending on my free time
- Maintaining the datapack for newer versions
- Adding config for things like changing/removing the warning message, the damage type/ammount, etc.
- Adding a warning near the world border (last ring's border)
- Modifying health and damage factors to allow values over 100 and under 0
Warning
Due to datapack limitations I used an approximation of the square root to calculate the distance, this approximation should work fine for distances 0 - 10000 blocks but beyond distance between rings may start getting smaller.
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.21.6, 1.21.7, 1.21.8
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — see the MC Java Mods guides for the full walkthrough.
- Downloads as Radii_5.zip
- Download size: 11 KB
- Download link checked 8 Sept 2026 — working
These come from our own check of the pack file, not from the source page.