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Control Mods New (1.20+)

Introduction

FxControl no longer exists on 1.20. It's functionality has been merged into InControl

YouTube Tutorial for 1.16 and higher: YouTube Link

In Control is a mod that supports a rule based system that allows you to control various aspects about mobs. There are rule files to control spawning, loot, experience and so on.

Both mods have support for:

Because both mods have a very similar structure the documentation for them is merged.

Common Questions (FAQ)

  • Q: How can I add spawns using spawn.json?

    • A: You can't. spawn.json can only RESTRICT spawns. To add spawns you use the new spawner.json
    • A: spawner.json is used to ADD spawns. spawn.json is used to RESTRICT spawns

  • Q: Why can't I seem to control mobs from mod 'X' using spawn.json?

    • A: Occasionally modded mobs don't follow the rules completely. It may help in such situations to use 'when': 'onjoin' in your rule

  • Q: I added a rule to spawn.json to allow a mod but nothing is happening. Why is that?

    • A: 'Allow' is standard. With spawn.json you can only restrict spawns that were already happening. If you want to add more spawns you'll have to add rules to spawner.json (possibly refined with rules in spawn.json)
    • A: Having only 'allow' rules in spawn.json is (usually) pretty useless as those mobs will spawn anyway (exceptions are if you want to boost mobs). Typically, you want to have 'deny' rules

  • Q: I'm trying /summon and spawn eggs but my rules don't seem to work?

    • A: In Control only affects natural spawns and spawns done by mob spawners. Eggs and /summon is not affected

  • Q: How can I get zombies to spawn more often?

    • A: This question is asked so much that it really is considered a FAQ. As I already told you above you can't add spawns using spawn.json alone. You need to add a rule to spawner.json and possibly set conditions in spawn.json. See the examples at the bottom of this wiki.

  • Q: I set the Minecraft time to a certain day but In Control rules don't seem to notice?

    • A: In Control uses an internal day counter which is not the same as the Minecraft day. You can use the /incontrol days command to see the current day and also to set it

Differences between the 1.20 version and older

In 1.20 InControl was changed heavily due to some new spawning events in Forge. In addition FxControl has been removed and has been merged into InControl.

The following changes were made:

  • There is a new keyword for 'spawn.json' called 'when'. This flag determines when the spawn check will occur. See the documentation later in this wiki.
  • 'special.json' has been removed. It's functionality has been merged into 'spawn.json' by using the new 'when' field with the 'finalize' value
  • The 'onjoin' keyword has been removed. It's functionality has been merged into 'spawn.json' by using the new 'when' field with the 'onjoin' value

Changelogs

Here is a list of all (recent and important) changes to InControl and Fx Control:

  • 9 March 2024:
    • The 'structure' test now supports lists
    • New 'structuretags' test to support a (list of) structure tags
  • 27 Januari 2024:
    • New named number system where you have variables with a name and an integer value:
      • Two new commands: 'numbers' to show the current numbers and 'setnumber' to set a number
      • New 'number' test that can be used in almost all rules to test if a number satisfies a given expression
      • This test also works for events and spawner rules. Basically everwhere that you can test for a phase you can now also test for a number
      • New event action called 'number'. This will allow you to modify a number when an event happens
      • New 'changenumber' action that can be used in many rules. Same syntax as the number event action: "changenumber": "mycounter=+1"
    • Various fixes and improvements to the phase system:
      • Manually set phases will now also be persisted when the world is reloaded
      • New event action called 'phase'. This will allow you to set or clear a phase when an event happens. For example, you can now set a phase when a player kills a mob and then use that phase in a spawner rule to spawn mobs only when that phase is set
      • The 'phase' test is now also supported for experience, loot, effect, harvest, left click, right click, place, and summon aid rules
    • New custom event:
      • New 'customevent' action that you can use from within many rules to fire a custom event
      • New event trigger called 'custom'
      • New 'result' called 'deny_with_actions' which will deny the event but still execute the actions. This can be used to deny the spawn of a mob but still send out an event
  • 3 Nobember 2023:
    • New events.json system that allows the player to spawn mobs whenever something happens. Currently implemented 'mob_killed' and 'block_broken' events
    • New 'eventspawn' test in 'spawn.json' that can be used to test for mobs spawned by the new events.json system
    • Added new 'setphase', 'clearphase', and 'togglephase' actions for effects, experience, leftclicks, rightclicks, harvests, and spawn events
    • New area system in 'areas.json'. This can be used by map makers to define predefined locations on the map. These areas can then be used in various rules. For example to create a peaceful area on a server
    • New 'area' test that can be used in nearly all rules (like spawn.json, loot.json, effects.json, ...). This will evaluate to true if the position is in the specified area
    • Added new /incontrol area command to show the current area
    • Added 'setphase' and 'clearphase' commands
  • 9 Jul 2023:
    • In Control for 1.20 works differently then previous versions. "onjoin" is gone. Instead there is now "when" with four possible values 'position', 'onjoin', 'finalize', and 'despawn'
    • The 'special.json' file is gone. Instead you can now use 'spawn.json' for all your needs. Using 'when' at finalize you can now control the equipment and stats of mobs
    • Merged all FxControl functionality into InControl
  • 1 Jul 2023:
    • Added 'minlight_full' and 'maxlight_full' keywords. These are similar to 'minlight' and 'maxlight' but they will test the full light level (including the sky light level). 'minlight' and 'maxlight' only test block light level
  • 10 May 2023:
    • New 'addscoreboardtags' keyword for spawner.json and spawn.json. With this you can add scoreboard tags on each entity spawned by this rule
    • New 'scoreboardtags_all' and 'scoreboardtags_any' conditions for spawn, experience, loot, special, and summonaid. These will test if all or any of the given tags are present on the entity
    • New 'nodespawn' action for spawn, special, and summonaid. This will prevent the mob from despawning
    • New 'time', 'height', and 'light' keywords which are supported wherever the corresponding min/max versions are supported. Using these keywords you can do more precise testing on the specific values. The wiki will contain more documentation on this
    • The 'daycount' keyword now also supports this new expression syntax. Using this you can now do things like: 'spawn zombies for two days every 10 days and spawn creepers for one day in the same cycle'
    • Added new 'minverticaldist' and 'maxverticaldist' keywords to the spawner system. These will allow you to specify a vertical distance between the spawner and the spawn position
    • The spawner system will now fail if no dimensions are specified (as it should, it's not optional)
  • 30 April 2023:
    • Added new 'building' keyword that you can use to test as a condition. This will allow testing if (for example) a spawn is in a certain list of buildings
  • 28 April 2023:
    • Added support for the 'tag' keyword in a block description (in favor of the old and non functional 'ore' keyword)
  • 7 Feb 2023:
    • Added new 'validspawn' and 'sturdy' conditions to the spawner system. This avoids spawning mobs on slabs for example

Commands

These mods have various commands that allow you to debug and tweak what is going on:

  • incontrol reload: after editing the rule files you can use this command to reload it and reapply the new rules
  • incontrol debug: dumps debug info about spawning in the log. Warning! This can produce a lot of output
  • incontrol show: show all entities and their names that can be used in spawn.json for mob names
  • incontrol kill: kill all entities of a given type. Possible types are: 'all', 'hostile', 'passive', or 'entity'. It is also possible to give the name of an entity instead of a type (like 'minecraft:enderman'). There is also an optional extra parameter for a dimension ID
  • incontrol list: list all current mobs present in the current dimension (and how many there are of each type)
  • incontrol days: without parameters it shows the current day. You can also change the current day using this command
  • incontrol phases: this shows all currently active phases
  • incontrol setphase <phase>: set a phase
  • incontrol clearphase <phase>: clear a phase
  • incontrol numbers: show all currently active numbers
  • incontrol setnumber <name> <value>: set a number to a specific value
  • incontrol area: show the current area

Rule Files

All rule files can be found in the config/incontrol directory.

The following rule files are currently supported:

  • phases.json: with this file you can define sets of globally active common conditions (called phases). These phases can then be used in all following rules as a more efficient and clean way to select rules
  • spawn.json: with this file you can block spawning of certain creatures under certain conditions. In addition, when a spawn is allowed you can also alter some of the properties of the mob like maximum health and others. Note that the rules in this file only alter already existing spawns. You cannot (for example) with this file alone add blazes to spawn in the overworld. For that you need to look at spawner.json too
  • summonaid.json: this is a file that is structured the same as spawn.json but is only used when zombies are summoned for aid
  • spawner.json: this is a new spawning system (from 1.16.5 onwards) that you can use instead of the currently broken potentialspawn
  • loot.json: with this file you can control the loot that mobs drop when they are killed based on various criteria
  • experience.json: this file controls how much experience you get from killing mobs. It has a similar structure to loot.json except that you cannot control experience based on the type of damage (like magic, fire, explosion, ...)
  • effects.json: with this file you can add effects to the player based on various conditions
  • breakevents.json: with this file you can add effects to the player or world when a block is broken (and also prevent the block from breaking)
  • placeevents.json: with this file you can add effects to the player or world when a block is placed (and also prevent the block from being placed)
  • rightclicks.json: with this file you can add effects to the player or world when the player right-clicks a block (and also prevent interaction)
  • leftclicks.json: with this file you can add effects to the player or world when the player left-clicks a block (and also prevent interaction)
  • areas.json: with this file you can define named areas that can be used by the rules
  • events.json: with this file you can define events that allow you to spawn mobs whenever something happens. Currently implemented 'mob_killed', 'block_broken', and 'custom' events

spawn.json

With this rule file you can control various aspects of when a mob should spawn (or despawn). Note that you cannot use this file to add new mobs to the game. For that you need to use spawner.json too.

Rules in this file are essentially split into four different categories:

  • position: this is used to check if a mob is allowed to spawn in general. It's called by vanilla whenever a mob is about to spawn
  • onjoin: rules in this category are checked whenever a mob joins the world. This is a stronger check because it's also fired for spawn eggs and when a mob enters another dimension
  • finalize: this is the final step in spawning a mob. Rules in this category can change stats or equipment of the mob. You can also still cancel the spawn here
  • despawn: this is called whenever a mob is about to despawn. You can use this to prevent despawning

The category of a spawn rule is set with the new when keyword. This keyword is optional and defaults to position.

Some additional notes about spawn.json. Each rule has a result which can be allow, default, deny, or deny_with_actions. In case of deny the spawn will simply be canceled. The difference between allow and default is that with default some simple vanilla spawn restrictions (like not spawn inside a block) are still tested. When when is equal to finalize then the difference between default and allow is that default will still let the vanilla finalize operation do its job (for example, skeletons will still get their bow). If you use allow then only your own actions will be executed.

The difference between deny and deny_with_actions is that with deny no actions will be executed.

In addition, each rule can have a continue keyword. This will cause a matching rule to work but then continue processing potential different rules (remember! Rules are executed in order)

Rules are executed in order PER category! For every spawn that happens every rule is evalulated from top to bottom. The first rule that matches ALL the conditions will be executed and the rest is ignored (unless you use the continue keyword).

This does also mean that a rule of one category that is executed will not stop the execution of rules in other categories.

Some modded mobs don't do the proper events in all cases so it is possible you have to do use the onjoin category to get the desired effect (set when to onjoin).

Rule Structure

Every rule has three parts:

  • Conditions: This represents tests that have to be true before the rule can be considered for execution. All conditions in a rule have to be true before the rule will be executed
  • Actions: This represents things that will be done when the rule is executed
  • Extra: Some rules need extra things to work and some conditions/actions have extra modifiers that can alter how they work

Whenever something happens the corresponding rules are evaluated from top to bottom. In most cases the first rule that matches will be executed and further rules are ignored (the rules in spawner.json and loot.json are an exception to that. For these all matching rules are executed)

Expressions

In some of the conditions it is possible to use expressions. An expression is basically a string specifying some test to do on an integer value.

Here are a few examples:

  • >10: evaluate to true if the number we are testing on is greater than 10
  • !=10: evaluate to true if it is different from 10
  • 4-50: evaluate to true if the number is between 4 and 50 (inclusive)
  • 10: evaluate to true if the number is equal to 10

The following comparators are supported: >, >=, <, <=, =, and !=.

Numeric Expressions

A few keywords support numeric expressions. These are special expressions that are used to specify integer ranges. For example the daycount and time tests can use this. The following numeric expressions are supported:

  • greater or gt: evaluate to true if the number is greater than the specified value
  • greaterOrEqual or ge: evaluate to true if the number is greater than or equal to the specified value
  • smaller or lt: evaluate to true if the number is smaller than the specified value
  • smallerOrEqual or le: evaluate to true if the number is smaller than or equal to the specified value
  • equal or eq: evaluate to true if the number is equal to the specified value
  • notEqual or ne: evaluate to true if the number is not equal to the specified value
  • range: evaluate to true if the number is in the specified range
  • outsideRange: evaluate to true if the number is outside the specified range
  • repeat: evaluate to true if the number is in the specified cycle

To clarify this. Here are a few examples:

Day number between day 10 and 20 inclusive (both sides)

"daycount": "range(10,20)"

Time above 1000

"time": "gt(1000)"

Evalulate to true on the 3rd and 4th day every 10 days:

"daycount": "repeat(10,3,4)"

Item filters

Many conditions are very simple but when testing for items things can be a bit more complicated. That's why there is a specific syntax that can be used when testing on items. In this section we will go over all the possibilities and also present a few examples. In most cases when testing for an item (like test if the player holds a specific item in their hand) you can either use a single item filter or else a list of item filters. Let's talk about the case of an individual item filter. The following possibilities are supported:

  • minecraft:sand (just normal minecraft sand)
  • With NBT (same format as for /give command): minecraft:stained_hardened_clay{display:{Lore:[\"My Clay\"]}}
  • A JSON descriptor which supports the following tags:
    • item: an item ID (like minecraft:sand or rftools:powercell)
    • empty: a boolean (true or false) indicating if the item is empty or not. If this is present no other tags will be considered
    • damage: an expression (see above) which will be evaluated on the damage from the item
    • count: an expression which will be evaluated on the number of items in the stack
    • tag: a string indicating a block tag (for example minecraft:stone, forge:bookshelves, ...)
    • mod: a string indicating the modid for the item
    • energy: an expression which will be evaluated to the amount of Forge Energy present in the item
    • nbt: a JSON array. Every object in this array supports the following tags:
      • tag: the name of the NBT tag to test on (don't confuse this with the 'tag' above)
      • value: the stringified value of the NBT tag to test on
      • contains: use this instead of value in case the tag represents a list. The value after contains should be a JSON array which in turn contains nbt matching tags like what we're describing now (see example later to make this more clear)

Item Filter Examples

The following examples are all applied on playerhelditem but it is of course possible to use them for any kind of condition that supports items.

The simplest case. A simple stick:

{
  "playerhelditem": "minecraft:stick"
}

A list of different items:

{
  "playerhelditem": [ "minecraft:stone_pickaxe", "minecraft:stone_axe", "minecraft:stone_shovel", "minecraft:stone_sword" ]
}

The same block with some NBT data:

{
  "playerhelditem": "minecraft:stained_hardened_clay{display:{Lore:[\"My Clay\"]}}"
}

The same example specified with JSON:

{
  "playerhelditem": {
    "item": "minecraft:stained_hardened_clay",
    "nbt": [
      {
        "tag": "display",
        "value": "My Clay"
      }
    ]
  }
}

An empty hand:

{
  "playerhelditem": { "empty": true }
}

In this example we need a damage pickaxe:

{
  "playerhelditem": {
    "item": "minecraft:iron_pickaxe",
    "damage": ">0"
  }
}

In this final example we test if a pickaxe has a specific enchantment (unbreaking in this case):

{
  "playerhelditem": {
    "item": "minecraft:iron_pickaxe",
    "nbt": [
      {
        "tag": "ench",
        "contains": [
          {
            "tag": "id",
            "value": 34
          }
        ]
      }
    ]
  }
}

Block Filters

Similarly to item filters there is also the block condition that can test on the existence of a specific block. Like with items it is possible to specify a list or a single block filter. Here are the possibilities on an individual block filter:

  • minecraft:sand: a block matching this id. Metadata and/or properties are ignored
  • tag:forge:barrels/wooden: a block matching the specified tag
  • A JSON descriptor which supports the following tags:
    • block: a block ID (like minecraft:sand or rftools:powercell)
    • properties: (only if block is used). This is a JSON array with properties to match against. As soon as this is present a blockstate will be constructed made out of the block and the properties specified here and the match has to be exact. So properties that are not specified here will be put to their default value
    • tag: a string indicating a tag (for example forge:barrels/wooden, minecraft:planks, ...)
    • mod: a string indicating the modid for the block
    • energy: an expression which will be evaluated to the amount of Forge Energy present in the block
    • contains: either a single JSON object or else an array of JSON objects representing item filters as explained in the item filter section. The contains test will succeed if it finds any matching item in the inventory (if the block to test actually represents an inventory)
    • side: this is a modifier for both energy and contains. If present it will indicate the side from which we want to examine the energy or inventory contents. If not present the 'null' side is used. This should be a string like east, west, south, north, up, or down.

Block Filter Examples

A diamond block:

{
  "block": "minecraft:diamond_block"
}

A block of planks:

{
  "block": "tag:minecraft:planks"
}

Or in JSON syntax:

{
  "block": { "tag": "minecraft:planks" }
}

An RFTools powercell containing more than 1000000 energy:

{
  "block": {
    "block": "rftoolspower:powercell",
    "energy": ">1000000"
  }
}

A chest containing more than 10 sticks:

{
  "block": {
    "block": "minecraft:chest",
    "contains": {
      "item": "minecraft:stick",
      "count": ">10"
    }
  }
}

A powered button:

{
  "block": {
    "block": "minecraft:stone_button",
    "properties": [
      {
        "name": "powered",
        "value": "true"
      }
    ]
  }
}

Mob Counter

The maxcount and mincount tags to control mob spawning can be either a simple number or string containing a number and a mob, but it can also be a more complex JSON with various conditions. The following tags are supported:

  • amount: the amount to compare with (can be scaled!)
  • perplayer: if this is true the amount will be scaled with the amount of players present
  • perchunk: if this is true the amount will be scaled with the amount of loaded chunks divided by 289 (this is how vanilla mobcap works)
  • mod: if this is set all mobs of a given mod are counted (can be used in combination with hostile, passive, or all)
  • hostile: if this is set all hostile mobs are counted
  • passive: if this is set all passive mobs are counted
  • all: if this is set all mobs are counted
  • mob: this is a single mob or a list of mobs. If this is present only those mobs are counted

It's important to note that what is being counted depends on what you specify in the mincount or maxcount json. If you don't specifymod, hostile, passive, all, or mob then it will count the number of mobs of the same type as the mob that is being spawned.

However, as soon as you specify any of those keywords it will count what you specify. For example if you specify a skeleton mob inside the mincount block then it will count skeletons even if the counter is being used in a rule that spawns zombies.

Mob Counter Examples

In spawn.json: deny skeletons if there are already more then 50 hostile mobs present per player:

  {
    "dimension": "minecraft:overworld",
    "mob": "minecraft:skeleton",
    "mincount": {
      "amount": 50,
      "hostile": true,
      "perplayer": true
    },
    "result": "deny"
  }

In spawn.json: deny all mobs of a given mod if there are already more than 50 mods of that mod present, scaled based on vanilla mob cap rules:

  {
    "dimension": "minecraft:overworld",
    "mod": "horriblecreatures",
    "mincount": {
      "amount": 50,
      "mod": "horriblecreatures",
      "perchunk": true
    },
    "result": "deny"
  }

Contrast above example with the old syntax where it would compare the amount of each individual mob of the given mod:

  {
    "dimension": "minecraft:overworld",
    "mod": "horriblecreatures",
    "mincount": 50,
    "result": "deny"
  }

Conditions

In this section all possible conditions are explained. Some conditions are not usable in all rules. This will be mentioned here. Whenever a position is tested in a rule the given position depends on the rule. For mob spawns this will be the position where the mob will spawn. For block break events this will be the position of the broken block. For player effects this is the position of the block on which the player is standing.

Possible types:

  • S: a string
  • B: a boolean (true/false)
  • I: an integer
  • F: floating point number
  • E: is a string describing a numeric expression (see above for information on those)
  • [<type>]: a list of type (for example, [S] is a list of strings)
  • JSON: a JSON in a specific format explained elsewhere

The table below is very wide. Please scroll horizontally to see all fields.
NameTypespawnerspawnsummonlootexpharvestleftclickrightclickplaceeffectDescription
phaseS/[S]VVVVVVVVVVall phases that must be active for this rule to work. Phases are defined in phases.json. Putting conditions in a phase is more efficient and cleaner
numberJSONVVVVVVVVVVA json describing a numeric condition that must be valid before this rule can work. See the section on the numeric system for more information
whenSVcan be equal to 'position', 'finalize', 'onjoin', or 'despawn'. Default is 'position'
mindaycount / maxdaycountIVVVindicate the minimum (inclusive) or maximum day count. The day counter starts at 0 (see the days command)
daycountI/EVVVthis is true if the day counter is a multiple of the given parameter. It also supports an expression in which case the expression is evaluated (see more on numeric expressions above in this wiki)
babyBVVVtrue if this is a baby
spawnerBVtrue if spawned by a spawner
incontrolBVtrue if spawned by the In Control spawner system (spawner.json)
eventspawnBVtrue if spawned by the In Control event system (events.json)
area'S'VVVVVVVVVtest if the position is in a certain area (see areas.json)
minheight / maxheightIVVVVVVVVVVindicates the minimum (inclusive) or maximum height at which this rule will fire
heightEVVVVVVVVVVuses a numeric expression to test the height at which the mob will spawn
minlight / maxlightIVVVVVVVVVvalue between 0 and 15 indicating the minimum and maximum block light level on the given block
minlight_full / maxlight_fullIVVVVVVVVVvalue between 0 and 15 indicating the minimum and maximum full (combined block and sky) light level on the given block
lightEVVVVVVVVVuses a numeric expression to test the light level on the given block
mincount / maxcountS/I/JSONVVstring value that is either a number in which case it will count how many mobs of the given class are already in the world or else of the form <amount>,<mob> to count the number of mobs of that type. That way you can have a rule file based on the number of mobs already present. Note that instead of this syntax you can also use the JSON mob counter syntax as explained above
maxthis / maxtotal / maxpeaceful / maxhostile / maxneutral / maxlocalIVthe maximum amount of mobs of this type, in total, passive, hostile, neutral or local (spawn box around the player, as this is more expensive use this with care)
minspawndist / maxspawndistFVVVVVVVVVthe minimum or maximum distance (in minecraft units) to the spawn point in the world
mintime / maxtimeIVVVVVVVVVthe time of the day (a number between 0 and 23999)
timeEVVVVVVVVVuses a numeric expression to test the time of the day (see the numeric expression section higher up in this wiki)
mindifficulty / maxdifficultyFVVVVVVVVVthe local difficulty of the place where the mob will spawn. This is a number between 0 and 4
mindist / maxdistIVV?the minimum/maximum distance to the player for controlling the spawn. By default this is equal to 24/120
minverticaldist / maxverticaldistIVif specified you can use this to test for the vertical distance between the player and the position where the mob will spawn
canspawnhereBVa check that is specific to the entity implementation. This is called by Minecraft automatically if you return default as the result of this rule. For many mobs this check will do the standard light level check
norestrictionsBVremove the mob specific (usually light related) restrictions on spawning
inliquid / inwater / inlava / inairBVallow spawning in any liquid, water, lava, or in air. This will ignore the mob specific restrictions it might have on spawning
isnotcollidingBVa check that is specific to the entity implementation. This is called by Minecraft automatically if you return default as the result of this rule. For many mobs this check will do a test if the mob would collide with blocks after spawning
difficultySVVVVVVVVVone of the following values: easy, normal, hard, peaceful
weatherSVVVVVVVVVrain or thunder
categoryS/[S]VVVVVVVVVNOT for 1.19! One of the following values: none, taiga, extreme_hills, jungle, mesa, plains, savanna, icy, the_end, beach, forest, ocean, desert, river, swamp, mushroom, nether. This represents the category of the current biome
biometagsS/[S]VVVVVVVVVONLY for 1.19! This is a biome tag (or list of tags) which will be used to match with the biome. Example tags are: minecraft:is_ocean, minecraft:is_hill, minecraft:has_structure/igloo, minecraft:allows_surface_slime_spawns, forge:is_hot, forge:is_cold, forge:is_wet, ... and a LOT more
hostile / passiveBVVVVmatching only hostile or passive mobs
seeskyBVVVVVVVVVtrue if the block can see the sky (not in a cave)
slimeBVVtrue if this is a slime chunk (only for 1.18 or higher)
structureS/[S]VVVVVVVVVthe name of the structure to test for. This way you can make sure a rule only fires in a village for example. Some examples are minecraft:mineshaft, minecraft:village, and so on. Modded structures should also work
structuretagsS/[S]VVVVVVVVVthe name of the structure tag to test for. This way you can make sure a rule only fires in a village for example. Some examples are minecraft:mineshaft, minecraft:village, and so on. Modded structures should also work
mobS/[S]VVVVan ID for a mob like minecraft:creeper and so on. Modded mobs should also work
modS/[S]VVVVVVa mod id. By using this you can block spawns of mobs that belong to some mod. Use minecraft for vanilla mobs
blockS/[S]/JSONVVVVVVVVVa block filter as explained above
blockoffsetJSONVVVVVVVVVmodify the position of the block that is being used by the block test (or the setblock action). This JSON can contain tags like x, y, or z which will be added (as offset) to the original block position or else the boolean tag look in which case the position will be the position the player is looking at (only in case there is a player involved which isn't the case for spawn.json)
biomeS/[S]VVVVVVVVVthe biome of the current block (like minecraft:plains for example)
biometypeS/[S]VVVVVVVVVthe biome type (from the biome dictionary). Examples are WARN, COLD, ICY, DESERT, and DESERT_LEGACY
dimensionS/[S]VVVVVVVVVVthe dimension of the current block or player (for example minecraft:overworld)
dimensionmodS/[S]VVVVVVVVVthe mod of the dimension. You can use this to have a rule work in all dimensions from a given mod
randomFVVVVVVVVVthis will succeed rule if a random number is less then this number. So if you want to have a rule that fires with 10%chance then use 0.1 here
player / fakeplayer / realplayerBVVindicating if the mob was killed by a player (fake or real), a fake player (automation that behaves like a player) and a real player
projectile / explosion / magic / fireBVVindicating if the mob was killed by a projectile, explosion, magic or fire
sourceS/[S]VVthe damage source. Some sources are minecraft:lightning_bolt, minecraft:lava, minecraft:cactus, minecraft:wither, minecraft:hot_floor, ...
playerhelditem / offhanditem / bothhandsitemS/[S]/JSONVVVVVVVVVa representation of the item(s) that the player is holding in their main hand (or offhand). Use a correct item filter (or list of item filters)
lackhelditem / lackoffhanditemS/[S]/JSONVVVVVa representation of the item(s) that the player is not holding in their main hand (or offhand). Use a correct item filter (or list of item filters)
helmet / chestplate / leggings / bootsS/[S]/JSONVVVVVVVVVa representation of the item(s) that the player is having as armor. Use a correct item filter (or list of item filters)
lackhelmet / lackchestplate / lackleggings / lackbootsS/[S]/JSONVVVVVa representation of the item(s) that the player is not having as armor. Use a correct item filter (or list of item filters)
addscoreboardtagsS/[S]VVadd scoreboard tags to the spawned entity
scoreboardtags_all / scoreboardtags_anyS/[S]VVVVtest for scoreboard tags on the entity (all must be there or any must be there)
nodespawnBVVif this is given the mob will not despawn. Be careful with this!
incity / instreet / inbuilding / insphere (Lost Cities)BVVVVVVVVVcheck if the current position is in a city, street, building or city sphere
building (Lost Cities)S/[S]VVVVVVVVVcheck if the current position is in a specific building
gamestage (Gamestages)SVVVVVVVVthe current game stage. When a player is not really present (like with spawn.json) the closest player is used
winter / summer / spring / autumn (Serene Seasons)BVVVVVVVVVcheck the current season (NOT IMPLEMENTED IN 1.16)
amulet / ring / belt / trinket / charm / body / head (Baubles)S/[S]/JSONVVVVVVVVVcheck if an item is in a bauble slot (NOT IMPLEMENTED YET IN 1.16)
state / pstate (EnigmaScript)SVVthis can be used to test the value of a (player) state with a string like this state=value (NOT IMPLEMENTED YET IN 1.16)

Actions

In this section all the actions per rule type are listed.

The following actions are possible in all rules:

  • setphase: this is a string representing a phase that will be set
  • clearphase: this is a string representing a phase that will be cleared
  • togglephase: this is a string representing a phase that will be toggled
  • changenumber: this is a string representing a change for a number. See the number system section for more information
  • customevent: this is a string representing a custom event that will be fired. See the event system section for more information

Spawn and SummonAid

For spawn.json the following actions are supported:

  • result: this is either 'deny', 'allow', 'default', or not specified. If you don't specify a result then whatever other mob control mods have decided is preserved. If you specify a result then In Control will take over (since the In Control rule will fire last). Use 'deny' to block the spawn. If 'allow' is used then the spawn will be allowed even if vanilla would normally disallow it (i.e. too much light). If 'default' is used then it is possible the spawn can still be denied if there is not enough light for example. Unless 'deny' is used then you can use any of the following actions:
  • nbt: allows you to add NBT to a spawned mob
  • customname: allows you to set a custom name for the spawned mob
  • healthmultiply: this is a floating point number representing a multiplier for the maximum health of the mob that is spawned. Using 2 here for example would make the spawned mob twice as strong.
  • healthadd: this is a floating point number that is added to the maximum health
  • speedmultiply: this is a floating point number representing a multiplier for the speed of the mob
  • speedadd: this is a floating point number that is added to the speed
  • damagemultiply: this is a floating point number representing a multiplier for the damage that the mob does
  • damageadd: this is a floating point number that is added to the damage
  • angry: this is a boolean that indicates if the mob will be angry at and/or target the nearest player. For zombie pigman this will make them angry at the player immediatelly. Same for enderman and wolves
  • potion: this is either a single string or a list of strings. Every string represents a potion effect which is indicated like this: <potion>,<duration>,<amplifier>. For example "minecraft:invisibility,10,1"
  • helditem: this is either a single string or a list of strings. Every string represents a possible item that the spawned mob will carry in its hand. This works only with mobs that allow this like skeletons and zombies. You can also specify a weight with this by adding <number>= in front of the string. Like this: "1=minecraft:diamond_sword", "2=minecraft:iron_sword"
  • armorboots: this is either a single string or a list of strings representing random armor that the spawned mob will wear
  • armorhelmet: is either a single string or a list of strings representing random armor that the spawned mob will wear
  • armorlegs: is either a single string or a list of strings representing random armor that the spawned mob will wear
  • armorchest: is either a single string or a list of strings representing random armor that the spawned mob will wear

In addition, gamestage, playerhelditem, and related tags (which are tied to a player) are also supported. In that case the nearest player will be used as the basis for deciding the rule.

Loot Control

In contrast with most other rule files every rule is evaluated every time. i.e. a successful loot rule doesn't prevent the other loot rules from firing. Loot supports the following actions:

  • item: this is a string or a list of strings representing new loot that will be dropped
  • itemcount: this is a string representing how many items should drop (optionally depending on looting level). For example: 5/7-10/20-30 will drop 5 items at looting 0, 7-10 items at looting 1 and 20-30 items at looting 2 or beyond
  • nbt: this is a JSON specifying the NBT that will be used for the loot items
  • remove: this is a string or a list of strings representing items to remove from the loot
  • removeall: if this is present then all items will be removed from the loot (before new items are added by this rule)

Experience

This is similar to loot control except that it controls how much experience you get from killing a mob. All keywords from loot control can be used here except the ones that are about damage type (magic, explosion, ...) as that information is not present in this event. There are four outputs that work for these rules:

  • result: set this to 'deny' to not give any experience at all
  • setxp: set a fixed XP instead of the default one
  • multxp: multiply the normal XP with this number
  • addxp: after multiplying the normal XP add this amount to the final XP

Effects

With effects, you can specify an additional timeout keyword in the rule. This represents the number of ticks that will be waited before testing the rule again. Keep in mind that some of these rules can be expensive so using a higher timeout will make the rule fire less frequently.

Then there are a number of actions:

  • explosion: this is a string as follows: <strength>,<flaming>,<smoking>. For example 10,true,true and it will cause an explosion with the given strength
  • setblock: this is a JSON with a block description to place: { 'block': 'minecraft:chest', 'properties': { 'name': 'facing', 'value': 'west' } }
  • give: this is either a single string or a list of strings. Every string represents a possible item that the player will get. You can also specify a weight with this by adding <number>= in front of the string. Like this: 1=minecraft:diamond_sword, 2=minecraft:iron_sword
  • drop: this is either a single string or a list of strings. Every string represents a possible item that will be dropped. You can also specify a weight with this by adding <number>= in front of the string. Like this: 1=minecraft:diamond_sword, 2=minecraft:iron_sword
  • potion: this is either a single string or a list of strings. Every string represents a potion effect which is indicated like this: <potion>,<duration>,<amplifier>. For example minecraft:invisibility,10,1
  • fire: this is an integer representing the number of seconds that the player should be put on fire
  • clear: clear all potion effects
  • message: give a message to the player
  • damage: this is a string with a damage source name followed by an amount of damage. For example fall=1.0 which would give 1.0 fall damage. All vanilla damage sources are supported (like 'inFire', 'lightningBolt', 'lava', 'cramming', outOfWorld', 'magic', ...)
  • setstate: if EnigmaScript is present this can be used to set a state with a string like this state=value
  • setpstate: if EnigmaScript is present this can be used to set a player state with a string like this state=value
  • command: this is a string representing a command that will be executed. The @p will be replaced with the player name. For example give @p minecraft:diamond_sword
  • addstage: this is a string representing a game stage that will be added to the player
  • removestage: this is a string representing a game stage that will be removed from the player

Break and Place

There is no timeout keyword here. In addition to the actions that you can do for effects this also has a result output which can be allow or deny. Note that (in contrast with spawn.json) the other actions are still executed even if the rule says deny!

Left click and Right click

There is no timeout keyword here. In addition to the actions that you can do for effects this also has a result output which can be allow or deny. Note that (in contrast with spawn.json) the other actions are still executed even if the rule says deny!

Phase System

The phase system allows you to define global conditions and give them a name. In Control rules can then use these phases so that they are only active if one or more phases are active. This is much more efficient as the global conditions are evaluated once every 10 ticks as opposed to every time a mob tries to spawn. In addition, it is much cleaner. Phases only work with a limited set of conditions (only conditions that are globally true):

  • time, mintime and maxtime
  • daycount, mindaycount and maxdaycount
  • weather
  • winter, summer, spring, and autumn
  • state

Since 1.20.1 it is now also possible to set phases from spawn.json or some other rule files. Note that these phases should be separate from the phases defined in phases.json because otherwise setting them will have no effect.

Number System

The number system is similar to the phase system in that it is also state that is remembered by In Control and that can be used in various places (rules, spawner, event system) to conditionally allow or disallow the execution of a rule. Numbers are basically integers with a name and a value. The value can be changed by various systems (like the 'changenumber' action in a rule or the 'number' action in an event).

When a number is used as a condition (either in a rule or in a condition for an event) then it is a JSON object with the following keys:

  • name: the name of the number
  • expression: an expression in which the number will be used. See the numeric expression section higher up in this wiki for more information

For example. Here is a condition that tests if a number is larger then 10:

{
  "name": "counter",
  "expression": "gt(10)"
}

When a number is set to a value (either in a rule or in an action for an event) then it is a string which basically represents a series of operators and operands. Examples are the best way to explain this.

In case of a rule (like spawn.json):

Add 1 to a number called counter:

{
  ...
  "changenumber": "counter=+1"
}

Or from events. Here we set a specific number to a constant value:

{
  "name": "counter",
  "value": "10"
}

Increase the number with 1:

{
  "name": "counter",
  "value": "+1"
}

Multiply the number with 2 and subtract 1:

{
  "name": "counter",
  "value": "*2-1"
}

Areas

Areas are defined in areas.json and can be used in various rules like spawn.json. There are two types of areas: box and sphere. Check the example below to see how you can define an area. You can also use the incontrol area command to see if you are in an area in game.

Events

Events are a new powerful system that allows you to spawn mobs when something happens. Currently the block_broken, mob_killed, and custom events are supported.

Events are defined in events.json and have the following structure:

  • on: this is a string representing the event that will trigger this event. Currently the following events are supported:
    • block_broken: this event is triggered when a block is broken
    • mob_killed: this event is triggered when a mob is killed
    • custom: this is a custom event as fired from any rule where customevent is used
  • parameters: this is a JSON object with parameters that are specific to the event. See below for more information.
  • conditions: this is a JSON object with generic conditions. The following keys are supported:
    • dimension: this is a string or a list of strings representing the dimension(s) in which the event will trigger
    • random: this is a floating point number between 0 and 1 representing the chance that the event will trigger
    • phase: this is a string or a list of strings representing the phase(s) that must be active for the event to trigger
    • number: this is a json object (or a list) with two keys:
      • name: the name of the number to test
      • expression: an expression in which the number will be used. See the numeric expression section higher up in this wiki for more information
  • spawn: this is an optional JSON object with the following structure:
    • mob: this is a string or a list of strings representing the mob(s) that will be spawned
    • mincount/maxcount: the minimum/maximum amount of mobs to spawn. Default is 1 for both
    • mindistance/maxdistance: the minimum/maximum distance from the event to spawn the mob
    • attempts: the number of attempts to spawn the mob. Default is 10
    • norestrictions: if this is true then the mob specific restrictions on spawning are ignored
  • phase: this is an optional JSON object with the following structure:
    • set: this is a boolean indicating if the phase(s) will be set. If this is not specified then it is assumed to be true
    • names: this is a string or a list of strings representing the phase(s) that will be set or cleared
  • number: this is an optional JSON object with the following structure:
    • name: the name of the number to change
    • value: this is a value in a special format. See below for more information

The value as used in the number action is a string which basically represents a series of operators and operands. This is explained in the section about numbers above.

Mobs spawned through this system will still go through spawn.json and can be distinguished with the eventspawn tag.

The mob_killed event supports the following parameters:

  • mob: this is a string or a list of strings for the mob to detect
  • player: this is a boolean indicating if the player should be the one that kills the mob

The block_broken event supports the following parameters:

  • block: this is a json object for the block that has to be broken

See the examples below on how to use this.

The custom event supports the following parameters:

  • name: this is a string representing the name of the custom event

Custom Spawner System (spawner.json)

Starting with 1.16 In Control supports a new spawning system that replaces the potentialspawn system. Rules of this type are put in spawner.json. Every rule in this file represents an option for one of more mobs to spawn under certain circumstances. The spawning system works per dimension and only attempts to spawn mobs every second.

Warning! spawner.json only supports the keywords mentioned here. Don't use ANY other keyword here. Other conditions (like biome) have to be specified in spawn.json.

Every spawner rule has two parts:

  • A part describing what will be spawned and how often the rule will fire
  • A part describing conditions for spawning

The following JSON keys are possible in the root of every rule:

  • phase: a string or list of strings representing all phases that must be active for this rule to work
  • number: a JSON object or a list of JSON objects containing a 'name' and 'expression' key. This is a numeric expression that will be evaluated and if it is true then the rule will work. See the numeric expression section higher up in this wiki for more information
  • mob: a single mob or list of mobs (like 'minecraft:zombie'). The entire rule will be evalulated for every mob specified in this list. This is a required setting
  • weights: an optional list of weights which will be used in combination with the mobs specified by 'mob'. By using weights you can give some spawns more importance
  • mobsfrombiome: this is a string that can be equal to 'monster', 'creature', 'ambient', 'water_creature', 'water_ambient', or 'misc'. Use this instead of specifying 'mob' manually. This will let the spawn take a random mob (given weight) that is valid for the current biome
  • addscoreboardtags: this is string or list of strings that can be used to add scoreboard tags to the spawned entity.
  • attempts: the number of times In Control will attempt to find a good position to spawn the mob. By default, this is 1
  • persecond: a floating point number indicating the chance of this rule firing. If this is 0.5 then there is 50% chance that this rule will spawn a mob (meaning that on average it will fire every 2 seconds). The default of this value is 1 (which means the rules fire onces per second). The maximum is also 1
  • amount: a JSON object containing a 'minimum', 'maximum' and an optional 'groupdistance'. This is the number of mobs that the spawnwer will attempt to spawn at once. The default is 1 for both. If 'groupdistance' is set then these mobs will spawn in groups (near each other). Note that 'groupdistance' is only for 1.18 and higher
  • conditions: a JSON object containing a set of conditions (see below)

The following JSON keys are possible in the conditions block (and ONLY those, for other conditions combine with regular spawn rules):

Warning! Don't depend on the defaults here! Best is to specify all the conditions so you're sure things are allright. Especially 'dimension' since that is mandatory!
  • dimension: a single dimension or list of dimensions (like 'minecraft:overworld'). This is required. If you don't specify any dimensions then nothing will happen
  • mindaycount and maxdaycount: the minimum/maximum daycount to allow this rule to work
  • mindist and maxdist: the minimum/maximum distance to the player for controlling the spawn. By default, this is equal to 24/120.
  • minverticaldist and maxverticaldist: the minimum/maximum vertical distance to the player for controlling the spawn.
  • minheight and maxheight: the minimum/maximum height of the spawn. By default, this is 1/256
  • norestrictions: remove the mob specific (usually light related) restrictions on spawning
  • inliquid: if true then allow spawning in any liquid (this will ignore the mob specific restrictions it might have on spawning in liquids)
  • inwater: if true then allow spawning in water (this will ignore the mob specific restrictions it might have on spawning in liquids)
  • inlava: if true then allow spawning in lava (this will ignore the mob specific restrictions it might have on spawning in liquids)
  • inair: if true then allow spawning in the air
  • maxthis: the maximum amount of mobs of the given type
  • maxtotal: the maximum amount of mobs total
  • maxpeaceful: the maximum amount of passive mobs
  • maxhostile: the maximum amount of hostile mobs
  • maxneutral: the maximum amount of neutral mobs
  • maxlocal: this will cause counting in the spawn box around the player. This is somewhat more expensive so use with care
  • validspawn: this will add a stronger check to the possible spawn positions to make sure the block is solid as well as correct light and other mob/block specific conditions.
  • sturdy: this will add a stronger check to the possible spawn positions to make sure the block is sturdy (not a slab for example)

Examples

Sometimes it is best to explain things with examples. In this section we will present many examples that you can use as a basis to make your own rules:

Using areas for safe spawn

Using this in areas.json you can define a safe zone around spawn:

[
  {
    "dimension": "minecraft:overworld",
    "name": "spawn",
    "type": "box",
    "x": 0,
    "y": 60,
    "z": 0,
    "dimx": 50,
    "dimy": 50,
    "dimz": 50
  }
]

And then in spawn.json:

[
  {
    "hostile": true,
    "area": "spawn",
    "when": "onjoin",
    "result": "deny"
  }
]

Phases for time control

Define a phase that is true if we are after day 10. You can then use this phase in all In Control rules:

[
  {
    "name": "after_day10",
    "conditions": {
        "mindaycount": 10
    }
  }
]

Define phases depending on a 10 day cycle and where in the cycle we are. These phases can then be used by spawner.json (for example) to spawn the correct creatures:

[
  {
    "name": "zombietime",
    "conditions": {
      "daycount": "repeat(10,0,1)"
    }
  },
  {
    "name": "creepertime",
    "conditions": {
      "daycount": "repeat(10,2,3)"
    }
  },
  {
    "name": "skeletontime",
    "conditions": {
      "daycount": "repeat(10,4,5)"
    }
  }
]

Spawns: allow only in plains biome

Here are some examples for spawn.json.

This example allows only spawns in plains biomes. All other spawns are prevented:

[
  {
    "biome": "minecraft:plains",
    "result": "allow"
  },
  {
    "result": "deny"
  }
]

Spawn: prevent too many zombies

Simple script to disable spawns of a particular type of mob if there are too many (not more then 10):

[
  {
    "mob": "minecraft:zombie",
    "mincount": 10,
    "result": "deny"
  }
]

Prevent all zombies based on the total number of hostile mobs. i.e. no zombies spawn if there are already more then 50 hostile mobs:

[
  {
    "mob": "minecraft:zombie",
    "mincount": {
      "amount": 50,
      "hostile": true
    },
    "result": "deny"
  }
]

Just prevent all zombies. Nothing else is changed:

[
  {
    "mob": "minecraft:zombie",
    "result": "deny"
  }
]

Just prevent all zombies, even from spawners. This is a much stronger test. Nothing else is changed:

[
  {
    "mob": "minecraft:zombie",
    "when": "onjoin",
    "result": "deny"
  }
]

Spawn: prevent all passive mobs in a dimension

This example prevents ALL passive mob spawns in a certain dimension:

[
  {
    "passive": true,
    "dimension": "dimensionmod:funkydim",
    "when": "onjoin",
    "result": "deny"
  }
]

Spawn: allow some specific mobs only

Only allow creepers, skeletons and passive mobs:

[
  {
    "mob": ["minecraft:creeper", "minecraft:skeleton"],
    "result": "default"
  },
  {
    "passive": true,
    "result": "default"
  },
  {
    "result": "deny"
  }
]

Spawn: allow based on height

Disallow hostile mob spawns above 50. Below 50 only allow spawns on stone and cobblestone:

[
  {
    "minheight": 50,
    "hostile": true,
    "result": "deny"
  },
  {
    "maxheight": 50,
    "block": ["minecraft:stone", "minecraft:cobblestone"],
    "result": "allow"
  },
  {
    "result": "deny"
  }
]

Spawn: beefed up mobs

Make all mobs on the surface very dangerous. Underground there is a small chance of spawning invisible but weak zombies. In addition, zombies and skeleton on the surface spawn with helmets, so they don't burn:

[
  {
    "mob": ["minecraft:skeleton","minecraft:zombie"],
    "seesky": true,
    "when": "finalize",
    "result": "allow",
    "healthmultiply": 2,
    "damagemultiply": 2,
    "speedmultiply": 2,
    "armorhelmet": ["minecraft:iron_helmet", "minecraft:golden_helmet"]
  },
  {
    "seesky": true,
    "hostile": true,
    "when": "finalize",
    "result": "allow",
    "healthmultiply": 2,
    "damagemultiply": 2,
    "speedmultiply": 2
  },
  {
    "seesky": false,
    "random": 0.1,
    "when": "finalize",
    "mob": "minecraft:zombie",
    "result": "allow",
    "healthmultiply": 0.5,
    "potion": "minecraft:invisibility,10000,1"
  }
]

Make all zombies slower but have more health:

[
  {
    "mob": "minecraft:zombie",
    "result": "default",
    "when": "finalize",
    "healthmultiply": 2,
    "nbt": {
      "Attributes": [
        {
          "Base": 0.23,
          "Modifiers": [
            {
              "Operation": 2,
              "Amount": -0.5,
              "Name": "effect.moveSlowdown 0"
            }
          ],
          "Name": "generic.movementSpeed"
        }
      ]
    }
  }
]

Loot examples

Here are some examples for loot.json.

Make blazes only spawn blaze rods if they are killed by a player in a nether fortress. The amount of blazerods will be higher if the looting level is higher:

[
  {
    "mob": "minecraft:blaze",
    "remove": "minecraft:blaze_rod"
  },
  {
    "mob": "minecraft:blaze",
    "structure": "Fortress",
    "player": true,
    "item": "minecraft:blaze_rod",
    "itemcount": "2-3/3-4/4-6"
  }
]

Let the wither only drop a netherstar if it is killed with a stick:

[
  {
    "mob": "minecraft:wither",
    "remove": "minecraft:nether_star"
  },
  {
    "mob": "minecraft:wither",
    "player": true,
    "helditem": "minecraft:stick",
    "item": "minecraft:nether_star"
  }
]

In this example zombies will drop an enchanted diamond sword:

  {
    "mob": "minecraft:zombie",
    "player": true,
    "item": "minecraft:diamond_sword",
    "nbt": {
      "ench": [
        {
          "lvl": 3,
          "id": 22
        }
      ]
    }
  }

Effect examples

Here are a few examples for effects.json:

This example makes the player get poison effect if they are outside in the overworld. They will be put on fire if they goe to the nether, and they will get the slowness effect if they are holding a stone tool:

[
  {
    "timeout": 20,
    "dimension": "minecraft:overworld",
    "seesky": true,
    "potion": "minecraft:poison,21,1"
  },
  {
    "timeout": 20,
    "dimension": "minecraft:the_nether",
    "fire": 20
  },
  {
    "timeout": 20,
    "helditem": [ "minecraft:stone_pickaxe", "minecraft:stone_axe", "minecraft:stone_shovel", "minecraft:stone_sword" ],
    "potion": "minecraft:slowness,21,3"
  }
]

In the following example the player will get hurt if they stand on an RFTools powercell that has a lot of energy in it:

[
  {
    "timeout": 10,
    "block": {
      "block": "rftoolspower:dimensionalcell_simple",
      "energy": ">10000"
    },
    "damage": "minecraft:hot_floor=3"
  }
]

With this example the player will be put on fire if they even look at lava:

[
  {
    "timeout": 10,
    "blockoffset": {
      "look": true
    },
    "block": "minecraft:lava",
    "fire": 20
  }
]

Break Events

Here are a few examples for breakevents.json:

This example prevents the player from breaking diamond ore with an iron pickaxe:

[
 {
   "playerhelditem": "minecraft:iron_pickaxe",
   "block": "minecraft:diamond_ore",
   "message": "You cannot mine this!",
   "result": "deny"
 }
]

In the next example diamond ore can only be broken with an undamaged pickaxe:

[
  {
    "playerhelditem": {
      "item": "minecraft:iron_pickaxe",
      "damage": ">=1"
    },
    "block": "minecraft:diamond_ore",
    "message": "You cannot mine this!",
    "result": "deny"
  }
]

And in this example the pickaxe has to be enchanted with a specific enchantment:

[
  {
    "playerhelditem": {
      "item": "minecraft:iron_pickaxe",
      "nbt": [
        {
          "tag": "ench",
          "contains": [
            {
              "tag": "id",
              "value": 34
            }
          ]
        }
      ]
    },
    "block": "minecraft:diamond_ore",
    "result": "allow"
  },
  {
    "block": "minecraft:diamond_ore",
    "message": "You cannot mine this!",
    "result": "deny"
  }
]

With 50% chance give an extra diamond when the player mines a diamond ore block:

[
  {
    "playerhelditem": {
      "item": "minecraft:diamond_pickaxe"
    },
    "block": "minecraft:diamond_ore",
    "random": 0.5,
    "give": "minecraft:diamond",
    "result": "allow"
  }
]

Right Click examples

Here are a few examples for rightclicks.json:

In this example the player can only open chests with a stick in his or her hand:

[
 {
   "playerhelditem": "minecraft:stick",
   "block": "minecraft:chest",
   "result": "allow"
 },
 {
   "block": "minecraft:chest",
   "message": "The chest is locked!",
   "result": "deny"
 }
]

If we extend this example with another rule then we can also make sure that the chest can be opened without sticks provided the chest itself contains sufficient sticks:

[
  {
    "playerhelditem": "minecraft:stick",
    "block": "minecraft:chest",
    "result": "allow"
  },
  {
    "block": {
      "block": "minecraft:chest",
      "contains": {
        "item": "minecraft:stick",
        "count": ">10"
      }
    },
    "result": "allow"
  },
  {
    "block": "minecraft:chest",
    "message": "The chest is locked!",
    "result": "deny"
  }
]

Events: spawn chickens when a cow is killed

In this example we spawn a random amount of chickens when a cow is killed:

[
  {
    "on": "mob_killed",
    "parameters": {
      "mob": "minecraft:cow",
      "player": true
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "random": 0.3
    },
    "spawn": {
      "mob": "minecraft:chicken",
      "mindistance": 3,
      "maxdistance": 5,
      "mincount": 2,
      "maxcount": 3,
      "attempts": 20
    }
  }
]

Events: spawn wither skeleton when diamond ore is broken

In this example we possibly spawn a wither skeleton when we break a diamond ore block:

[
  {
    "on": "block_broken",
    "parameters": {
      "block": {
        "block": "minecraft:diamond_ore"
      }
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "random": 0.3
    },
    "spawn": {
      "mob": "minecraft:wither_skeleton",
      "mindistance": 0,
      "maxdistance": 2,
      "attempts": 20,
      "norestrictions": true
    }
  }
]

Spawner: spawn villagers in water

Spawns random villagers near the player in water. Using groupdistance these villager groups will spawn near each other (only for 1.18 and higher):

[
  {
    "mob": "minecraft:villager",
    "persecond": 0.5,
    "attempts": 20,
    "amount": {
      "minimum": 2,
      "maximum": 5,
      "groupdistance": 3
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "inwater": true,
      "mindist": 5,
      "maxdist": 20,
      "minheight": 45,
      "maxheight": 175,
      "maxthis": 20
    }
  }
]

Spawner: increase hostile mob spawns after day 20

In the following example we globally increase hostile mob spawns after day 20 (using phases).

First phases.json:

[
  {
    "name": "after_day20",
    "conditions": {
        "mindaycount": 20
    }
  }
]

Then spawner.json:

[
  {
    "phase": "after_day20",
    "mobsfrombiome": "monster",
    "persecond": 0.5,
    "attempts": 20,
    "amount": {
      "minimum": 2,
      "maximum": 5
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "maxhostile": 200
    }
  }
]

Spawner: advanced example, extra mobs in deserts

Here is a more advanced example where spawn.json and spawner.json are used together to get full control. Let's say you want to spawn some extra mobs in deserts but otherwise keep vanilla spawn rates the same. So first add a rule to spawner.json to add new spawns. Basically we add skeletons and zombies with a maximum of 100 per mob (so maximum 100 skeletons and maximum 100 zombies):

[
  {
    "mob": ["minecraft:skeleton", "minecraft:zombie"],
    "persecond": 0.5,
    "attempts": 20,
    "amount": {
      "minimum": 2,
      "maximum": 5
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "mindist": 25,
      "maxdist": 100,
      "minheight": 15,
      "maxheight": 200,
      "maxthis": 100
    }
  }
]

But we only want these extra mobs in deserts. So you could do this in spawn.json:

[
  {
    "mob": ["minecraft:skeleton", "minecraft:zombie"],
    "dimension": "minecraft:overworld",
    "biome": "minecraft:desert",
    "result": "default"
  },
  {
    "mob": ["minecraft:skeleton", "minecraft:zombie"],
    "dimension": "minecraft:overworld",
    "result": "deny"
  }
]

But that's not good. These two rules will allow the zombies and skeletons to spawn in the desert, but they will get denies everywhere else. We don't want to touch spawns of zombies and skeletons outside deserts. So let's modify the rules in spawn.json:

[
  {
    "mob": ["minecraft:skeleton", "minecraft:zombie"],
    "dimension": "minecraft:overworld",
    "biome": "minecraft:desert",
    "result": "default"
  },
  {
    "mob": ["minecraft:skeleton", "minecraft:zombie"],
    "dimension": "minecraft:overworld",
    "incontrol": true,
    "result": "deny"
  }
]

Basically by adding "incontrol": true to the second rule we will only deny spawns outside deserts if they were spawned by In Control. All normal mob spawns will stay normal.

Getting Zombies to spawn more

This is commonly requested so I decided to add an example here. First you need to add a rule to spawner.json to make them spawn more. This can be done with the following rule. This will make zombies spawn up to a maximum of 200. Using 'norestrictions' should also make them spawn during daylight:

[
  {
    "mob": "minecraft:zombie",
    "persecond": 0.5,
    "attempts": 20,
    "amount": {
      "minimum": 2,
      "maximum": 5
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "norestrictions": true,
      "mindist": 25,
      "maxdist": 100,
      "minheight": 15,
      "maxheight": 200,
      "maxthis": 200
    }
  }
]

If needed you can then use rules in spawn.json to control when and how they spawn. For example, let's make them spawn more on the surface and less in caves (but they can still spawn there). Let's also say that we don't want to spawn any zombies in the first 5 days after starting the world:

[
  {
    "mob": "minecraft:zombie",
    "daycount": "lt(5)",
    "result": "deny"
  },
  {
    "mob": "minecraft:zombie",
    "seesky": true,
    "result": "default"
  },
  {
    "mob": "minecraft:zombie",
    "random": 0.8,
    "result": "deny"
  }
]

Making a dangerous world after spawning a wither

As soon as a wither is spawned in the world we want to make the world more dangerous and start spawning wither skeletons. First in spawn.json we detect if a wither is spawned and then we set the wither phase:

[
  {
    "mob": "minecraft:wither",
    "when": "onjoin",
    "setphase": "wither",
    "result": "default"
  }
]

Then in spawner.json we start spawning wither skeletons as soon as the wither phase is set:

[
  {
    "mob": "minecraft:wither_skeleton",
    "persecond": 5,
    "attempts": 20,
    "phase": "wither",
    "amount": {
      "minimum": 1,
      "maximum": 1
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "mindist": 20,
      "maxdist": 90,
      "minheight": -64,
      "maxheight": 256,
      "maxthis": 10
    }
  }
]

Changing what a spawner spawns

In this example we change zombie spawners so that they spawn chickens instead:

In spawn.json we add a rule for spawns from zombies and send out a custom event called chicken_instead. We use deny_with_actions as a result because we want to deny the spawn but still call the custom event action.

  {
    "mob": "minecraft:zombie",
    "spawner": true,
    "customevent": "chicken_instead",
    "when": "onjoin",
    "result": "deny_with_actions"
  }

In events.json we add a rule for the custom event chicken_instead and we spawn a chicken instead of a zombie:

  {
    "on": "custom",
    "parameters": {
      "name": "chicken_instead"
    },
    "conditions": {
      "dimension": "minecraft:overworld"
    },
    "spawn": {
      "mob": "minecraft:chicken",
      "mindistance": 0,
      "maxdistance": 2,
      "mincount": 1,
      "maxcount": 1,
      "attempts": 20,
      "norestrictions": true
    }
  }

Spawning wither skeletons as soon as too many diamond ore blocks are mined

First we define an event to count whenever a diamond ore block is broken. Add this to events.json:

[
  {
    "on": "block_broken",
    "parameters": {
      "block": {
        "block": "minecraft:diamond_ore"
      }
    },
    "conditions": {
      "dimension": "minecraft:overworld"
    },
    "number": {
      "name": "diamonds",
      "value": "+1"
    }
  }
]

Instead of this we could also have added a rule to breakevents.json to count the number of diamonds:

[
  {
    "block": "minecraft:diamond_ore",
    "changenumber": "diamonds=+1"
  }
]

Then in spawner.json we add spawning of wither skeletons as soon as the number is high enough:

[
  {
    "mob": "minecraft:wither_skeleton",
    "number": {
      "name": "diamonds",
      "expression": "gt(100)"
    },
    "persecond": 1,
    "attempts": 20,
    "amount": {
      "minimum": 1,
      "maximum": 1
    },
    "conditions": {
      "dimension": "minecraft:overworld",
      "mindist": 20,
      "maxdist": 90,
      "minheight": -64,
      "maxheight": 256,
      "maxthis": 10
    }
  }
]