Fretux's Skill Engine
by fretux
Fretux's Skill Engine is a Forge framework for building skill trees, which Ascend-based progression and other mods can use to define their own nodes.
What it does
The framework lets other mods create customizable skill trees. A mod registers its own skill nodes by adding JSON files, and the Skill Tree GUI positions, displays, zooms and pans them automatically. Node icons can use custom textures or vanilla item textures.
Node activation runs on the server and its results are synced to each client. The UI shows requirement tooltips and overlays, and nodes can be linked to one another. Ascend is required, so Fretux's Skill Engine works alongside its progression system. The mod is published for Forge only, for Minecraft 1.20.1, with 1.4.9 as the latest file from 2026-10-08. It is open source under the MIT License and runs on client and server.
Key features
Skill tree framework
Skill trees are built from nodes that other mods define, with attribute requirements and linked nodes.
Server-synced node activation
Node activation and skill point handling run on the server, and the results are synced to connected clients.
Custom node icons
Icons can be drawn from custom textures or from vanilla item textures.
Automatic tree detection
The engine detects added trees and displays them in the Skill Tree GUI without manual registration.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 1
Use cases
Addon skill trees
Mod authors can create complete skill trees for their own mods through the simple API, without touching internal classes.
Who it’s for: Mod developers who want to add skill trees to their own content, and server owners who run addons that depend on the framework.
How it compares
Peritia is also a Forge option for 1.20.1, open source under the MIT License and run on client and server. SkillTreeCore covers 1.16.5 – 1.20.1 on Forge and NeoForge, is not open source and is released under All rights reserved. Epic Engine is a Forge mod for 1.20.1 under a custom license, not open source, and also runs on client and server.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Fretux's Skill Engine | Forge | 1.20.1 | Client and server | 2026-10-08 |
| Peritia | Forge | 1.20.1 | Client and server | 2025-08-22 |
| SkillTreeCore | Forge and NeoForge | 1.16.5 – 1.20.1 | Client and server | 2026-10-11 |
| Epic Engine | Forge | 1.20.1 | Client and server | 2025-07-22 |
Questions
Does Fretux's Skill Engine need Ascend?
Does the mod have to be installed on the server?
Which Minecraft versions does it support?
In the catalog
Fretux's Skill Engine is one of 3,514 Library mods on ModsFinder, and one of 1,576 Library mods for Forge. 34,764 mods support Minecraft 1.20.1.
More from fretux
Similar mods
What the author says
Skill Engine is not a standalone progression mod. It does not add gameplay, attributes, or abilities by itself. If you're looking for a mod that adds skills, this is not it.
Official listing
- Modrinth page
- modrinth.com/mod/fretux-skill-engine
- Owner
- fretux
- Published
- 2025-11-25
- Updated on Modrinth
- 2026-10-08
- Facts verified
- 2026-10-15