Fiw Bosses
by Fi3w0
Fiw Bosses is a data-driven framework for building custom multi-phase bosses, minions and fight flows, configured through JSON files rather than code.
What it does
Bosses are defined with HP-threshold phases, each with its own ability loadout, speed, damage, equipment, minion pool, transition messages, sounds and particles. Custom minions carry their own AI modes, gear, abilities and loot, and escort the boss or hold a position during the fight. Fight flow covers dialogue, pre-fight lines, a dormant boss that stays invulnerable until a player right-clicks it, and last words before it falls. Abilities, skins and dialogue can be reloaded while the game runs, so a tweaked file can be tested without restarting.
The framework is open source under the GNU General Public License v3.0 only and runs on client and server, so the server and every player need it. Files are published for Fabric, Forge and NeoForge across the 1.20.1 – 1.21.11 range, with builds for 1.20.1, 1.21.1, 1.21.8 and 1.21.11. Fabric API is required on Fabric and must be installed alongside the mod. Source code, an issue tracker and a wiki are linked from the project.
Key features
Phase-based boss fights
Bosses switch phases at HP thresholds, and each phase can change speed, damage, equipment and abilities.
Over 50 abilities
A library of more than fifty abilities can be combined into per-phase loadouts without writing code.
Eight movement styles
Movement styles include aggressive striking, defensive guarding, teleporting between points, hovering, long-range sniping and berserk rushing, alongside classic strafing and vanilla pathing.
Custom minions
Minions have their own skins, gear, abilities, AI modes and loot, and can be summoned quickly or during a phase change.
Disguises
A boss or minion can be rendered as a vanilla or modded mob, or as a real player skin, while keeping the full framework logic.
Damage protection rules
Damage multipliers can be set per boss, per phase and per minion, keyed to weapon, item or damage type.
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
Questions
Does Fiw Bosses need Fabric API?
Which loader and version should a server use?
Do bosses need to be coded in Java?
In the catalog
Fiw Bosses is one of 11,058 Mobs mods on ModsFinder, and one of 5,189 Mobs mods for Fabric. 19,862 mods support Minecraft 1.21.11.
More from Fi3w0
Similar mods
What the author says
Phases. Minions. Loot. Dialogue. Custom skins. 50+ abilities. No Java. No restarts. No combat-modding degree required. Vanilla has three bosses. You've beaten all of them.
Official listing
- Modrinth page
- modrinth.com/mod/fiw-bosses
- Owner
- Fi3w0
- Published
- 2026-03-11
- Updated on Modrinth
- 2026-10-14
- Facts verified
- 2026-10-15