
Fretux's Skill Engine
A framework for making skilltrees
Screenshots


About this Mod
Skill Engine
Skill Engine is not a standalone progression mod.
It does not add gameplay, attributes, or abilities by itself.
Instead, Skill Engine is a framework designed to let other mods create their own highly customizable skill trees, complete with:
- Node unlocking
- Attribute requirements
- Custom icons
- Skill point handling
- Server synchronization
- Requirements & tooltips
- Interaction with other progression systems (like Ascend)
If you're looking for a mod that adds skills, this is not it.
If you are a developer who wants to add skill trees to your mod without reinventing everything, Skill Engine is exactly what you need.
Features
JSON-driven Skill Tree System
Mods can register their own skill nodes simply by adding JSON files under:
data/<yourmodid>/skillnodes/*.json
Automatic Node Rendering
Nodes are positioned, displayed, zoomed, panned, and drawn automatically in the Skill Tree GUI.
Icons Support
Use your own textures or vanilla item textures as node icons.
Requirements System
Nodes can specify:
- Linked nodes
- Prerequisite attributes
- Skill costs
- Custom tags
The UI automatically displays requirements in tooltips and overlays.
Unlock Logic & Sync
Unlocking is fully handled server-side and synced to the client.
Full API Support
Skill Engine includes a public API class that allows other mods to:
- Give skill points
- Unlock skill nodes
- Check unlock state
- Access player skill data
- Register or reference nodes
How to Use Skill Engine in Your Mod
Skill Engine is designed to be extremely easy to integrate.
1. Add Skill Engine as a Dependency
In your mods.toml:
[[dependencies.yourmodid]]
modId="skillengine"
type="required"
versionRange="[1.0.0,)"
In your Gradle build:
implementation fg.deobf("net.fretux.skillengine:SkillEngine:<version>")
2. Create Your Skill Nodes (JSON)
Example:
{
"title": "Basic Strength",
"description": "You feel your muscles tighten.",
"cost": 1,
"position": { "x": -150.0, "y": -50.0 },
"links": ["skillengine:welcome"],
"tags": ["yourmodid:strength_1"],
"icons": "minecraft:textures/item/iron_sword.png",
"prerequisites": {
"strength": 10,
"agility": 5
}
}
Place this in:
data/yourmodid/skillnodes/basic_strength.json
Skill Engine will automatically detect it and add it to the tree.
3. Use the API in Your Code
Skill Engine exposes a simple API:
SkillEngineAPI.unlockNode(player, SkillEngineAPI.rl("yourmodid", "basic_strength"));
SkillEngineAPI.addSkillPoints(player, 3);
boolean unlocked = SkillEngineAPI.isUnlocked(player, SkillEngineAPI.id("welcome"));
You can interact with the system without touching internal classes.
Skill Engine does nothing by itself.
It does not add a skill tree or abilities on its own.
You only need this mod if:
- A mod you play depends on Skill Engine
- You want to install addons that create skill trees
Available Versions
How to Install Fretux's Skill Engine on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set forge Loader
In the panel under "Egg", select the forge loader and matching Minecraft version (1.20.1).
Install Mod
Open the mod browser in the dashboard and search for "Fretux's Skill Engine". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.20.1
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
Fretux's Skill Engine server crashes on startup – what to do?
Most common cause: wrong forge version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.20.1). You can switch loaders with one click in the panel.
Is Fretux's Skill Engine compatible with forge?
Fretux's Skill Engine officially supports forge for Minecraft 1.20.1. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Fretux's Skill Engine – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Fretux's Skill Engine consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
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Rent Modded Server
Install Fretux's Skill Engine with just one click on your server.