# Leukocyte
\nLeukocyte is a simple world protection mod for Fabric providing optional integration with player-roles.<\/p>\n
The basis of world protection with leukocyte is an “authority”. An authority is responsible for applying specific rules
\nto players within it. An authority has a unique name, as well as a priority (“level”), and set of player exclusions. <\/p>\n
### creating authorities An authority can be later removed with `\/protect remove ### setting rules To set a rule as `allow` or `deny` on an authority, use `\/protect set rule For example: `\/protect set example place deny` will disallow block placement within the authority named `example`.<\/p>\n ### making shapes To start, run: `\/protect shape start`. This will begin the construction of a shape. These commands can be run multiple times to compose your shape.<\/p>\n Once you have finished composing a shape, you can run: `\/protect shape finish This shape can be removed in the future with `\/protect shape remove ### setting levels This is where levels come in: a level is just any number, where a higher level indicates higher priority, and a lower level indicates lower priority. Levels can be set on an authority with: `\/protect set level ### adding exclusions This is achieved through running: `\/protect exclusion add These exclusions can additionally be later removed with `\/protect exclusion remove`.<\/p>\n ### putting it together: an example Our example server will want to have global grief protection, except in our survival dimension and free-build areas. Let’s consider the two dimensions: `minecraft:overworld` and `example:survival`, as well as the role `builders`.<\/p>\n First, let’s create an authority named `global`. Since we will mostly want protection everywhere, it makes sense to Next, we can set the rules on this authority: Done! Now, let’s override this behavior in our survival dimension. But wait..! How will the mod know to apply the rules of `global` or `survival`, since `global` also applies in the survival dimension? Now we can similarly add our free build areas as exclusions too! Let’s say we have two free build areas, creatively named `free_build_1` and `free_build_2`. Next, let’s compose the shape for `free_build_1`: And repeat the same for `free_build_2`: Done! Now the free-build areas should be editable by any player- except, we want to create exclusions such that we can ‘ban’ players from the areas. With that, all our protection should be set up nicely! \ud83d\ude42<\/p>\n ### testing! querying and checking rules A few commands may come in handy: Server-side, region-based protection controllable by API or commands<\/p>\n","protected":false},"featured_media":93325,"template":"","meta":{"_minecraft_slug":"leukocyte","_minecraft_project_id":"hsRVgp6Q","_minecraft_author":"Patbox","_minecraft_license":"LGPL-3.0-only","_minecraft_downloads":8296,"_minecraft_follows":49,"_minecraft_client_side":"unsupported","_minecraft_server_side":"required","_minecraft_storage_type":"zip","_minecraft_archive_name":"leukocyte.zip","_minecraft_size_bytes":4291876,"_minecraft_version_count":17,"_minecraft_updated_at":"2026-05-16T22:20:53.492321Z","_minecraft_date_created":"2021-12-17T18:13:44.590742Z","_minecraft_date_modified":"2026-05-03T21:41:26.915998Z","_minecraft_project_url":"https:\/\/modrinth.com\/mod\/leukocyte","_minecraft_icon_attachment_id":93325,"_minecraft_imported_at":"2026-06-05T08:04:28+00:00","_minecraft_import_hash":"6719180801b88d2e8d5452cad38aa670","_minecraft_versions":"","_minecraft_links":"","_minecraft_gallery":"","_minecraft_api_metadata":""},"mod_category":[97,126,98,92],"mod_loader":[99,100],"minecraft_version":[51,53,54,55,57,58,690,59,36,60,94,102,37,40,74,38,78,80,81,82,163],"class_list":["post-93324","mod","type-mod","status-publish","has-post-thumbnail","hentry","mod_category-fabric","mod_category-management","mod_category-quilt","mod_category-utility","mod_loader-fabric","mod_loader-quilt","minecraft_version-1-18","minecraft_version-1-18-2","minecraft_version-1-19","minecraft_version-1-19-1","minecraft_version-1-19-3","minecraft_version-1-19-4","minecraft_version-1-19-4-rc2","minecraft_version-1-20","minecraft_version-1-20-1","minecraft_version-1-20-2","minecraft_version-1-20-4","minecraft_version-1-20-6","minecraft_version-1-21-1","minecraft_version-1-21-10","minecraft_version-1-21-3","minecraft_version-1-21-4","minecraft_version-1-21-5","minecraft_version-1-21-7","minecraft_version-1-21-8","minecraft_version-1-21-9","minecraft_version-26-1-2"],"yoast_head":"\n
\nTo create an empty authority, run: `\/protect add
\nAlternatively, an authority can be created to apply within a specific area like:
\n – `\/protect add
\n – `\/protect add
\n – `\/protect add
\nLeukocyte provides various rules that can be applied within authorities. These rules are:
\n – `break` controls whether players can break blocks
\n – `place` controls whether players can place blocks
\n – `block_drops` controls whether blocks drop items when broken
\n – `interact_blocks` controls whether players can interact with blocks
\n – `interact_entities` controls whether players can interact with entities
\n – `interact` controls global interaction over blocks and entities
\n – `attack` controls whether players can attack other entities
\n – `pvp` controls whether players can attack other players
\n – `portals` controls whether players can construct portals
\n – `crafting` controls whether players can craft items
\n – `fall_damage` controls whether players should receive fall damage
\n – `hunger` controls whether players will become hungry
\n – `throw_items` controls whether players can throw items from their inventory
\n – `pickup_items` controls whether items can be picked up by players or other entities
\n – `unstable_tnt` controls tnt automatically igniting when placed
\n – `ignite_tnt` controls whether tnt can be ignited
\n – `spawn_withers` controls whether withers can be summoned
\n – `fire_tick` controls whether fire tick is enabled within the authority. Defaults to gamerule if not set
\n – `fluid_flow` controls whether fluids flow
\n – `ice_melt` controls whether ice and frosted ice melt<\/p>\n
\nOften, you may want to protect an area with a weird shape that is not just a simple box.
\nTo achieve this, it is possible to combine multiple simple shapes into a more complex one which will be used to apply rules.<\/p>\n
\nNext, to add primitives to this shape, run:
\n – `\/protect shape add universe` to add the universe into this shape
\n – `\/protect shape add
\n – `\/protect shape add
\nThis will add a shape with the given name to the given authority.<\/p>\n
\nWhen dealing with multiple authorities, you may want one to take priority over another.
\nFor example, you may want a global authority to disallow griefing everywhere *except* specific areas for building.<\/p>\n
\nGiven an authority with a level of -1, an overlapping authority with a level of 10 will override the rules of the first.<\/p>\n
\nIt may not be desirable for the rules of an authority to apply to everyone.
\nIn this case, it is possible to exclude specific players, or entire roles from being affected by a given authority.<\/p>\n
\nThat was a lot of things! Let’s put this knowledge together on a simple example.<\/p>\n
\nWe additionally want to be able to exclude certain players from building in the free-build areas by use of a role.<\/p>\n
\nglobally apply protection and then specifically override this in specific areas.
\n – `\/protect add global with universe`<\/p>\n
\n – `\/protect set rule global place deny`
\n – `\/protect set rule global break deny`<\/p>\n
\n – `\/protect add survival with example:survival`
\n – `\/protect set rule survival place allow`
\n – `\/protect set rule survival break allow`<\/p>\n
\nHere, we can make use of levels: the default level for an authority is `0`, and a larger value means higher priority.
\nSo: let’s set the level of our `global` authority to `-1` such that anything we add in the future overrides it by default.
\n – `\/protect set level global -1`<\/p>\n
\nFirst, we should create an empty authority that applies to both of them, since they both have the same rules.
\n – `\/protect add free_build`
\n – `\/protect set rule free_build place allow`
\n – `\/protect set rule free_build break allow`<\/p>\n
\n – `\/protect shape start`
\n – `\/protect shape add -10 0 -10 10 255 10`
\n … and add it to our authority
\n – `\/protect shape finish free_build_1 to free_build`<\/p>\n
\n – `\/protect shape start`
\n – `\/protect shape add -100 0 -10 90 255 10`
\n … and add it to our authority
\n – `\/protect shape finish free_build_2 to free_build`<\/p>\n
\nLet’s do that with a `free_build_banned` role:
\n – `\/protect exclusion add free_build role free_build_banned`<\/p>\n
\nOkay, we’ve set up authorities, but how can we easily check which rules are set and by what?<\/p>\n
\n – `\/protect test`: tests all the rules that apply at a given location, and shows from which authority they originate
\n – `\/protect list`: lists all authorities in the world
\n – `\/protect display