Zone Creator

Zone Creator lets you define zones in your world with simple JSON files. In each zone, choose which mobs spawn, who can hurt whom, which potion effects apply, how mobs are equipped, what they drop, and what can be built or broken.

Split your world into zones and decide the rules of each one with simple JSON files. Mob spawning, damage, potion effects, mob equipment, loot, building… everything is set zone by zone, with no complicated commands and no interface.

Minecraft 1.20.1 · Forge 47.2.0+ · Server and singleplayer · No client-side mod required

1. The idea

You create a folder = you create a zone. In this folder, you drop small JSON files. Each file takes care of one subject:

config/zonecreator/
└── my_zone/
    ├── zone.json        ← the switch, the dimension, the priority
    ├── shape.json       ← WHERE the zone is (cube, sphere, polygon…)
    ├── damage.json      ← who can hurt whom
    ├── effects.json     ← potion effects
    └── …                ← only the files you need

Anything you do not write stays normal (vanilla). A missing file, a missing option: the mod touches nothing. You only change what you want to change.

Examples of what you can do:

• a monster-free zone around your village, where nobody fights;
• a PvP arena where only players can hurt each other;
• a toxic zone with poison for players and zombies in diamond armor;
• a mining field where only ore can be broken, even in adventure mode;
• a night zone where skeletons drop sand on top of their usual loot.

2. Installation

1. Install Forge 1.20.1 (47.2.0 or newer).
2. Put the Zone Creator .jar file in the mods folder.
3. Launch the game once: the config/zonecreator/ folder is created automatically with example zones.
4. Open the files, edit them, then type /zonecreator reload in game to apply the changes without restarting.

The mod is server-side only: on a server, players have nothing to install. It also works in singleplayer.

The folders created on first launch:

All the explanations inside the files are written in French and in English.

3. How it works

Creating a zone in 4 steps

1. Copy the zone_template folder and give it any name you like (for example my_village).
2. In zone.json, set json_enabled to true.
3. In shape.json, write where the zone is.
4. Add the rules you want in the other files, then type /zonecreator reload.

The master switch: json_enabled

At the very top of zone.json:

"json_enabled": false

This is why the example zones ship set to false: they change nothing in your world until you enable them.

Keys that start with _

Any key that starts with an underscore (_comment, _reference, _info…) is documentation: the mod ignores it. You can add your own to write yourself notes.

4. The three golden rules

Rule 1: true, false or neutral

Almost every option accepts three values:

Neutral is not "false". false actively forbids, neutral leaves the decision to other rules.

Rule 2: the highest-priority zone wins… option by option

When several zones overlap, they complement each other. For each option, the mod looks at the zones from the highest priority to the lowest and takes the first one that has an opinion (that is not neutral).

• Zone A (priority 50): fall: false
• Zone B (priority 10): fire: false, fall: true

At the same spot you get: fall damage blocked (A wins), fire damage blocked (only B talks about it).

How the mod sorts the zones:

Rule 3: "nothing written = vanilla"

• Missing file → everything neutral.
• Missing option → neutral.
• The mod never changes what you did not write.

5. The files of a zone

zone.json in detail

bypass (useful for admins):

conditions:

When the condition is not met, the whole zone is switched off (and the leave messages are sent).

6. Zone shapes

In shape.json, the shape key describes the zone. Seven shapes are available:

Good to know

• For cuboid, both corners are included: from [0,…,0] to [9,…,9] you get exactly 10 × 10 blocks. The order of the corners does not matter.
• Coordinates are read with the F3 key in game.
• A chunk coordinate is the block coordinate divided by 16.

The polygon, explained simply

Imagine you look at your zone from the sky and place stakes at its corners. Each point is [x, z]. The mod joins the points in order, and the last point connects back to the first. y_min and y_max give the height.

An "L" with 6 points:

  (500,500) ──────── (560,500)
      │                  │
      │                  │
      │              (560,530)
      │                  │
      │      (530,530) ──┘
      │          │
      │          │
  (500,580) ─── (530,580)

{
  "type": "polygon",
  "points": [[500,500],[560,500],[560,530],[530,530],[530,580],[500,580]],
  "y_min": -64,
  "y_max": 320
}

7. Who is targeted? (creatures, categories)

Many options ask who is concerned (targets, match, attacker, victim). It is written with a small block, called a "target":

The base categories

Your own categories (categories.json)

You can create your own categories (for example my_bosses). They are local to the zone and take priority over the base categories: if you reuse the name hostile, yours wins.

With not_affected_by you say: "members of this category escape the rules that target such-and-such category".

"categories": {
  "strength_immune": {
    "members": { "types": ["minecraft:zombie", "minecraft:ender_dragon"] },
    "not_affected_by": ["hostile"]
  }
}

Here, zombies and the Ender Dragon escape every rule that targets hostile (effects, damage, spawning).

8. All options, file by file

spawning.json: creature spawning

Two groups: hostile (monsters) and passive (animals, villagers). For each one, you choose a spawn reason:

all applies to everything; a specific reason overrides it, unless it is neutral (it then follows all).

"hostile": { "all": false, "spawn_egg": true }

→ No monster spawns, except with a spawn egg.

Spawning by command (/summon) is never blocked.

damage.json: damage

Who hurts whom (from the attacker to the victim):

Environment damage (in environment):

Multipliers (in multipliers): 1.0 = normal, 0.5 = half, 2.0 = double, 0 = no damage.

"multipliers": { "hostile_to_player": 1.25 }

Precise rules (in rules): when "all monsters" is too broad. Example: zombies do not hurt villagers, but still hurt players.

"rules": [
  { "attacker": {"type": "minecraft:zombie"}, "victim": {"type": "minecraft:villager"}, "allow": false },
  { "attacker": {"type": "minecraft:zombie"}, "victim": {"category": "player"},        "allow": true }
]

The first rule that matches decides.

effects.json: potion effects

Example of a random effect (good and bad mixed):

{ "pool": ["minecraft:speed", "minecraft:strength", "minecraft:slowness", "minecraft:weakness"],
  "state": true, "duration_ticks": 200, "interval_ticks": 200,
  "targets": {"category": "player"}, "remove_on_leave": true }

mob_modifiers.json: modifying mobs when they spawn

Two lists: modify (changes the mobs that spawn) and extra_spawns (adds mobs).

modify

Each equipment piece accepts item, enchantments and drop_chance (probability of dropping the piece on death).

extra_spawns: extra mobs (entity, weight, group_min, group_max, when). About every 5 seconds, with a chance for each player in the zone, a group spawns 24-48 blocks away from them (8 mobs of the same type at most around).

entity_rules.json: a specific creature

vanilla_loot + drops, what happens?

Players never lose their inventory because of this option.

blocks.json: breaking and placing blocks

Lists accept ids (minecraft:oak_planks) and tags (#minecraft:logs).

Even in adventure mode. The normal game prevents all building in adventure mode, and the client does not even try. Zone Creator works around this cleanly: a player in adventure mode who enters a zone that allows something is temporarily switched to survival, with the rule "everything that is not explicitly allowed stays forbidden", exactly like in adventure mode. They go back to adventure mode when leaving (or disconnecting).

{ "break_only": ["#minecraft:logs"], "place": false }

→ Only logs can be broken, and nothing can be placed.

messages.json: enter and leave

Messages are disabled by default in the examples.

commands.json: commands on enter and on leave

{ "on_enter": ["tellraw %player% {\"text\":\"Welcome\"}"], "on_leave": [] }

%player% is replaced by the player's name. Commands are run by the server.

9. Example 1

The goal: a large area where players are safe, do not fight, heal, and are not endangered by the environment. It is the zone that contains all the files, with all the explanations.

It ships with json_enabled: false. Set it to true to try it.

zone.json: the identity of the zone

shape.json: the shape

The file also contains a _shape_examples section with an example of each of the 7 shapes, ready to copy and paste.

spawning.json: no monsters

damage.json: a peaceful zone

effects.json: healing and protection

entity_rules.json: protected villagers

categories.json: two example categories

messages.json: ready but switched off

To enable them: enabled: true at the top of the file, and enabled: true in each message.

The other files

In short: what a player experiences in zone_safe

• They see no monsters spawn (unless they use an egg).
• Nobody can hurt them, and they cannot hurt anybody.
• They are healed continuously, and die neither from hunger nor from falling.
• Villagers are untouchable.
• Admins ignore all of this.

10. Example 2

The dangerous zone

The goal: a hostile, free-shaped zone (an "L"): poison, equipped monsters, more damage, no regeneration. It contains only the useful files: no messages.json, commands.json or entity_rules.json. What is missing is neutral.

It ships with json_enabled: false.

zone.json and shape.json

The 6 points of the "L":

spawning.json: monsters yes, animals no

damage.json: tougher monsters

effects.json: the toxic zone

Player effects (poison, slowness) disappear on leaving (remove_on_leave).

mob_modifiers.json: equipped monsters

Zombies: the "Toxic Zombie" (named "Zombie toxique" in the file)

Skeletons: the "Toxic Archer" (named "Archer toxique" in the file)

Extra mobs (extra_spawns)

In short: what a player experiences in zone_dangereuse

• They are poisoned permanently, slowed in the rain, and cannot regenerate.
• Zombies are "Toxic Zombies" in diamond armor, fast and tough.
• Skeletons are iron archers with a bow enchanted with Flame.
• Witches come to visit at night in the dark.
• Everything that hits them deals 25% more damage.
• No animals in sight.

11. Stacking several zones

Reminder: zones complement each other option by option. So you can stack zones at the same place to separate rules that do not share the same conditions.

A concrete case: "leather zombies at night, restricted building all day"

• During the day: only zone 6 is active, the block rules work.
• At night: both are active and complement each other: leather zombies + block rules.

Example: one zone overlapping another

The dangerous zone (priority 60) could overlap part of the safe zone (priority 50).

Tip: if you want a zone to "complement" the others without ever contradicting them, leave neutral everything that does not concern it.

The "whole dimension" zone

The zone_toutes_dimensions folder uses the dimension shape: its rules apply everywhere in the chosen dimension(s) ("dimension": "*" for all of them). It is always the lowest level: any zone with coordinates goes in front of it.

12. Commands

If a file has an error, the mod tells you which file and which option is the problem (up to 8 errors in the chat, the rest in latest.log), and everything that is correct keeps working.

13. Frequently asked questions and limits

- My rules do nothing, why? Check in this order: is json_enabled set to true? Is shape.json right (F3 for the coordinates)? Right dimension? Did you type /zonecreator reload? That command shows reading errors, and /zonecreator list shows which zones are really active.

- Should an admin ignore a zone? Yes: use bypass in zone.json (operators, game mode, player name or tag).

- Zombies do not spawn in my small zone. In a very small zone, natural spawning is rare. Test with spawn eggs (they work, because a missing reasons = all reasons).

- Why does minecraft:zombie not target drowned or husks? A type with a precise id only targets that creature. To target several, use a list or a tag.

- Does the mod work with other mods? Yes. The ids of creatures, items, blocks and effects from other mods work everywhere (e.g. "mymod:super_zombie").

- What does adventure mode do in a zone with blocks.json? See blocks.json. An adventure-mode player is temporarily switched to survival in zones that allow something, and goes back to adventure when leaving. Block rules apply according to the block's position, the mode switch according to the player's position.

Limits to know about

• Mob modifications (equipment, stats) are applied at spawn time. A mob that is already there is not modified.
• Effects are handled every 10 ticks (0.5 s) for creatures near players (96 blocks).
• Extra mobs (extra_spawns) are attempted about every 5 seconds.
• Block placing is checked for items placed by a player; explosions, endermen and other mobs are not covered by blocks.json.
• For a player temporarily switched to survival, a bypass by game mode still sees them as being in adventure mode.

   

  Notes

  • Lightweight mod
  • Server side

Mod created by Mozork. All rights reserved.