SimonUHC
by szymsun
SimonUHC lets a small group of friends play a round of ultra hardcore over LAN, with a preparation countdown and a configurable world border.
What it does
Players create a new world, open it to LAN and wait for friends to join before starting. A countdown set in the mod controls the preparation time, and a border command confines the playable area to a chosen size, such as a 5000 block square centered on the origin. Friends connect through the LAN session, and Essential's e4mc relay is supported for those who cannot reach the host directly.
The mod is a Fabric build for Minecraft 1.21.11 only, where client and server both need it. Players who join as spectators can watch the match and leave spectating whenever they choose, which is optional. The code is available as public source, and the license is Creative Commons Attribution 4.0, so the project is not open source.
Key features
LAN match hosting
A host opens a new world to LAN and friends join the same session to play a round together.
Preparation countdown
A countdown command sets how long players have to prepare before the border and match start.
Configurable world border
A border command sets the size of the playable area, for example confining the world to a 5000 block square.
Optional spectating
Spectators can join, watch the match and stop spectating at any time without affecting the players.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Friends on one LAN
A small group opens a world to LAN, sets a countdown and a border, then starts a round once everyone has joined.
Relay for remote friends
Players who cannot connect directly can use Essential's e4mc relay to join the same match.
Who it’s for: Players who want a short round with a few friends, and hosts who prefer to set the border and countdown themselves.
How it compares
Unlocked World Border is a Fabric mod for 1.21.4 – 1.21.11, released under the Apache License 2.0 and open source, and it works on client and server. Border cords checker is also Fabric, for 1.21.8 only, under the MIT License and open source, but it runs client-side only and adds no border of its own. BatleRoyalBorder is server-side only, for 1.21.8 only, under the GNU General Public License v3.0 only and open source. Only SimonUHC has a border command for a single match.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| SimonUHC | Fabric | 1.21.11 | Client and server | 2026-05-17 |
| Unlocked World Border | Fabric | 1.21.4 – 1.21.11 | Client and server | 2026-02-09 |
| Border cords checker | Fabric | 1.21.8 | Client-side only | 2025-12-09 |
| BatleRoyalBorder | Fabric | 1.21.8 | Server-side only | 2025-07-26 |
Questions
Does SimonUHC need to be installed on both sides?
Which game version does SimonUHC support?
Can friends join if they are not on the same network?
In the catalog
SimonUHC is one of 2,135 Minigame mods on ModsFinder, and one of 1,454 Minigame mods for Fabric. 19,862 mods support Minecraft 1.21.11.
Similar mods
Official listing
- Modrinth page
- modrinth.com/mod/simonuhc
- Owner
- szymsun
- Published
- 2026-05-16
- Updated on Modrinth
- 2026-05-17
- Facts verified
- 2026-10-15