Keystone Expansion Pufferfish's Skills
by Courone_mc
Keystone Expansion Pufferfish's Skills adds an MMO-style skill tree with eight progression categories, and it requires Pufferfish's Attributes and Pufferfish's Skills to run.
What it does
The mod extends the Puffish Skills tree with new progression categories covering Combat, Mining, Exploration, Farming, Crafting, Building, Magic and Taming. Each category carries long-term leveling curves that lead to endgame milestones and keystones, which are large nodes that change how a build plays.
Its trees are synergy-focused, so a player can choose between several paths such as tank, mobility, sustain or luck and XP builds, and combine them into different playstyles. The scaling follows the MMO model, aiming for build variety and a long progression arc in survival and modpack play. Pufferfish's Attributes and Pufferfish's Skills must be installed alongside it, and the mod is published for Fabric, Forge and NeoForge.
It is installed on the player's side alone, so servers need nothing. The code is not open source and is released under All rights reserved, with a public wiki linked from the listing. Builds cover 1.21.1 – 1.21.11 across ten release versions, and the latest file for every loader is 1.1.9 for 1.21.11, published on 2026-01-20.
Key features
Eight progression categories
Combat, Mining, Exploration, Farming, Crafting, Building, Magic and Taming each get their own branch of the tree.
Keystone nodes
Keystones sit at the endgame of a branch and reshape how the skills around them work.
Synergy-focused trees
Nodes are arranged so that picks in one branch strengthen the choices made in another.
Long-term leveling
Leveling curves stretch across the game so that progress continues after the early skills are opened.
Gallery
Compatibility
Latest build for each game version and loader.
1.21.x10 of 10 versions with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 2
How it compares
Default Skill Trees is server-side required with an optional client, is released under the CC0 1.0 Universal license and covers 1.18.2 – 26.2. Adventurer Skills is client and server, uses the MIT License and covers 1.18.2 – 26.3, so both sides need it. Cobblemon Pufferfish's Skills API is client and server on Fabric and NeoForge only, for 1.21.1, and is an API rather than a tree.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Keystone Expansion Pufferfish's Skills | Fabric, Forge and NeoForge | 1.21.1 – 1.21.11 | Client-side only | 2026-01-20 |
| Default Skill Trees | Fabric, Forge and NeoForge | 1.18.2 – 26.2 | Server required, client optional | 2026-01-11 |
| Adventurer Skills [Pufferfish's Skills] | Fabric, Forge and NeoForge | 1.18.2 – 26.3 | Client and server | 2026-04-29 |
| Cobblemon Pufferfish's Skills API | Fabric and NeoForge | 1.21.1 | Client and server | 2026-04-23 |
Questions
Which dependencies does Keystone Expansion need?
Does the server need the mod installed?
Which loaders and versions are supported?
In the catalog
Keystone Expansion Pufferfish's Skills is one of 3,514 Library mods on ModsFinder, and one of 2,348 Library mods for Fabric. 19,862 mods support Minecraft 1.21.11.
Similar mods
What the author says
Keystone Expansion is an MMORPG-inspired skill tree expansion for Puffish Skills, built to add long-term progression, build variety, and satisfying endgame power to survival modpacks. Enjoy the grind — and the dopamine when your build finally pops off.
Official listing
- Owner
- Courone_mc
- Published
- 2025-12-26
- Updated on Modrinth
- 2026-01-20
- Facts verified
- 2026-10-15