RCT Custom Series: Failrun
by Failsafe
RCT Custom Series: Failrun is a Cobblemon trainer series that adds custom trainer battles and trials, with a progression built around eight gyms and an Elite Four.
What it does
The series includes more than 80 custom trainers, of which about 40 are required to finish the main progression. The gym path follows an eight-gym structure that ends with an Elite Four and Champion battle, and it runs alongside Z-Crystal trials. An original antagonist team also appears in the progression.
Defeating the required trainers raises the level cap in steps, usually by 2 to 3 levels per milestone. Optional custom trials give rewards such as Mimikyunium Z, TMs and other Z-Crystals. Battles come in single, double and triple formats, and further optional trainers become available after the main story.
Only the server has to run the mod, and players may add it to their own game as well. Failrun is published for Fabric, Forge, NeoForge and Quilt, plus a data pack, with files for 1.21.1 only, and it is released under All rights reserved, so it is not open source. Its progression pairs with the Radical Trainers addon.
Key features
Eight-gym progression
Trainers follow an eight-gym path that leads to an Elite Four and Champion battle.
Custom trials and rewards
Optional trials give Z-Crystals, TMs and other items, and some trials offer experience and training items.
Single, double and triple battles
Trainer encounters use single, double or triple formats, and optional trainers remain available after the main story.
Incremental level cap
Defeating required trainers raises the level cap by a few levels at each milestone, pacing the team's growth.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Players looking for a difficult, progression-focused Cobblemon trainer campaign on 1.21.1, with a server that runs the mod.
How it compares
RCT Addon - Toppoh League Radical Cobblemon Trainers works on either side, and neither side needs it; it is released under the MIT License and is not open source, with files for 1.21.1 on Fabric, Forge, NeoForge and Quilt. Cobblemon Trainer Doubles is needed only by the server, not by players, under a custom license and not open source, covering 1.21.1 – 1.21.11 on Fabric and NeoForge only. Radical Cobblemon Trainers requires both the server and every player to run it, under a custom license and not open source, spanning 1.20.1 – 1.21.1 on Fabric, Forge and NeoForge.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| RCT Custom Series: Failrun | Fabric, Forge, NeoForge and Quilt | 1.21.1 | Server required, client optional | 2026-08-07 |
| RCT Addon - Toppoh League Radical Cobblemon Trainers | Fabric, Forge, NeoForge and Quilt | 1.21.1 | Server required, client optional | 2025-12-24 |
| Cobblemon Trainer Doubles | Fabric and NeoForge | 1.21.1 – 1.21.11 | Server required, client optional | 2026-10-06 |
| Radical Cobblemon Trainers | Fabric, Forge and NeoForge | 1.20.1 – 1.21.1 | Client and server | 2026-09-22 |
Questions
Does Failrun need Radical Trainers?
Does the server need Failrun?
Which loaders are supported?
More from Failsafe
What the author says
Failrun is a progression-focused trainer series addon for the Radical Trainers mod. The series includes over 80 custom trainers, with approximately 40 required to complete the main progression. Progression follows an 8-gym structure, followed by an Elite Four and Champion battle, alongside Z-Crystal trials and an…
Official listing
- Modrinth page
- modrinth.com/mod/failrun
- Owner
- Failsafe
- Published
- 2026-01-16
- Updated on Modrinth
- 2026-08-07
- Facts verified
- 2026-10-15