Predicator
by Nerjal_Nosk
Predicator lets server administrators restrict what players can do, using data-driven predicates tied to block breaking, block interaction, entity and item actions, and crafting.
What it does
Administrators define restrictions as predicates that match specific circumstances, and a predicate can then stop a player from performing the matching action. The restrictions cover block breaking, block interacting, attacking and interacting with entities, attacking and using items, and item crafting, including crafting through a grid crafting inventory or a crafting table. Because the rules are data-driven, they are written as data files rather than code.
Predicator extends the predicate tools that vanilla Minecraft already offers, adding text-based predicate conditions and number providers for more precise matching. Predicates can also be tied to tags, so a single tag can prevent players from doing a whole group of things. The mod is built on Unruled API, which must be installed alongside it. The author points to a wiki for details on how to write these predicates and to the features that rely on them.
Predicator runs on Fabric for 1.20.1 – 1.21.4, with the latest Fabric file, 0.8.1-1.21, targeting 1.21.4. It is released under the GNU General Public License v3.0 only and is open source, with public links to the source code, an issue tracker and a wiki. The mod works on either side, and neither the client nor the server needs it.
Key features
Action restrictions
Predicates can stop players from breaking or interacting with blocks and from attacking or interacting with entities.
Item controls
Attacking, using and crafting items can each be limited, including crafting in the inventory grid or at a crafting table.
Tag-based rules
Tags matched against predicates let one rule cover a whole group of circumstances.
Extended predicates
Text-based predicate conditions and number providers add finer matching than the vanilla predicate tools offer.
Compatibility
Latest build for each game version and loader.
1.21.x5 of 5 versions with builds
1.20.x6 of 6 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 1
Use cases
Protecting shared builds
A server owner can restrict block breaking or interaction in areas where players should not change anything.
Controlling item use
An administrator can limit which items players may use, attack with or craft.
Who it’s for: Predicator suits server owners and administrators who want to set rules for player actions through data files. Players on a server running it need nothing extra, since it is optional on the client.
Questions
Does Predicator need Unruled API?
Does Predicator have to be installed on both sides?
Where are the predicates configured?
In the catalog
Predicator is one of 5,392 Social mods on ModsFinder, and one of 4,084 Social mods for Fabric. 17,979 mods support Minecraft 1.21.4.
More from Nerjal_Nosk
Similar mods
What the author says
Data-driven means to add restrictions on what players can or cannot do. Register tags and matching predicates, to prevent your players from doing what you don't want them to in matching circumstances.
Official listing
- Modrinth page
- modrinth.com/mod/predicator
- Owner
- Nerjal_Nosk
- Published
- 2025-01-18
- Updated on Modrinth
- 2026-10-14
- Facts verified
- 2026-10-15