Help! Using Forge Tags in Datapacks Explained

Table of Contents

Introduction

Ever tried to add compatibility for your modded items to a datapack using Forge tags and got stuck? You’re not alone! Many Minecraft players, especially those venturing into the world of datapacks and modding, find themselves scratching their heads when it comes to utilizing Forge tags effectively. The interplay between datapacks and mods can be a powerful tool, allowing for extensive customization and integration. However, understanding the underlying mechanisms, such as Forge tags, is crucial to unlock this potential. This article aims to demystify Forge tags within the context of datapacks, providing a clear and practical guide to help you seamlessly integrate modded content into your custom Minecraft experiences. This knowledge is essential for any datapack creator wanting to ensure their creations work well with the vast array of mods available for Minecraft. Forge tags are the key to universal compatibility.

What are Forge Tags?

In the simplest terms, Forge tags are lists of items (or blocks, fluids, etc.) defined by the Forge modding platform. Think of them as categories that mods and datapacks can use to reference groups of items instead of having to list each item individually. They provide a centralized and organized way to manage modded content, ensuring compatibility and ease of use. Without Forge tags, datapacks would need to be painstakingly updated whenever a new mod adding similar items was introduced. The use of forge tags in datapacks provides a scalable and flexible solution.

Why Use Forge Tags in Datapacks?

The main reason to use Forge tags in datapacks is mod compatibility. Imagine you’re creating a custom crafting recipe that requires an iron ingot. Without Forge tags, you’d have to specify minecraft:iron_ingot. This works fine for vanilla Minecraft, but what about mods that add new types of iron ingots? Your recipe would be incompatible with those mods. By using the forge:ingots/iron tag, your recipe will automatically accept any item that is tagged as an iron ingot, regardless of which mod adds it. This immediately extends the reach of your datapack, making it more versatile and player-friendly.

Beyond mere compatibility, Forge tags also promote centralized lists and easy addition of new items. Instead of editing numerous recipes or advancements every time a new compatible item is added, you only need to update the Forge tag itself. This significantly simplifies maintenance and reduces the risk of errors.

Here are some common use cases for Forge tags in datapacks:

Crafting recipes involving modded materials: As mentioned above, this is a primary use case.
Defining items that can be used in a custom advancement: Reward players for obtaining any item from a specific Forge tag.
Defining what items a custom villager trade will accept: Create dynamic villager trades that can handle a variety of modded resources.
Configuring loot tables: Allow items from specific tags to appear as loot.

Purpose of this Article

This article aims to be your comprehensive guide to understanding and effectively using Forge tags in your datapacks. We’ll break down the complexities into manageable steps, providing clear explanations and practical examples that you can immediately apply to your own projects. We will focus on how to create, modify, and leverage Forge tags to ensure your datapacks are robust, compatible, and enjoyable for all Minecraft players, regardless of the mods they have installed. We want to help you become proficient in using forge tags in datapacks to unleash your creative potential.

Understanding Forge Tags Location

The core of Forge tags resides within the Minecraft directory. The first step is to locate the relevant files. Typically, these files are found in the .minecraft folder, specifically within the data/forge/tags directory. The exact location may vary slightly depending on your operating system and installation method. Understanding the directory structure is essential for efficiently managing and customizing your Forge tags.

Structure of the Tag Directory

The tags directory is further divided into subdirectories representing different tag types: items, blocks, fluids, and entity_types. Each of these subdirectories contains JSON files defining the individual tags. For instance, if you are looking for a tag related to iron ingots, you would navigate to data/forge/tags/items. Then the iron ingot tag is under forge/tags/items/ingots/iron.json

As an example, let’s say you want to find the tag for iron ingots. You would navigate to the data/forge/tags/items directory and look for a file named ingots/iron.json. This file contains the definition for the #forge:ingots/iron tag.

Tag File Structure JSON

Forge tags are defined using JSON (JavaScript Object Notation) files. The structure of these files is relatively simple, but understanding each component is crucial for correct usage.

Each tag file typically contains two main fields: replace and values. The basic structure looks like this:


{
  "replace": false,
  "values": [
    "minecraft:iron_ingot",
    "mymod:my_item",
    "#forge:ores/iron"
  ]
}

Let’s break down each field:

replace: This boolean field determines whether the tag should overwrite any existing tag with the same name. If set to true, the tag will completely replace any previous definition. If set to false, the tag will append to any existing definition. It’s generally recommended to set replace to false unless you specifically intend to overwrite an existing tag. Overwriting can cause compatibility issues with other mods or datapacks.
values: This array contains a list of item, block, or fluid IDs that belong to the tag. Each entry in the array can be either a specific item ID (e.g., "minecraft:iron_ingot") or a reference to another tag (e.g., "#forge:ores/iron"). When referencing another tag, you are essentially including all items in that tag within the current tag.

Understanding the Values Array

The values array is the heart of the Forge tag. It defines which items, blocks, or fluids are included in the tag. Each entry in the array must be a valid item, block, or fluid ID, or a reference to another existing tag. For example, to include a vanilla iron ingot, you would use "minecraft:iron_ingot". To include an item from a mod, you would use the mod’s item ID, such as "mymod:my_item". To include all items from another tag, you would use the # symbol followed by the tag’s name, such as "#forge:ores/iron".

Referencing other tags is a powerful way to create hierarchical relationships between tags. For example, you could create a tag called #mydatapack:special_ingots that includes both #forge:ingots/iron and #forge:ingots/gold.

Common Forge Tags Examples

Forge provides a range of commonly used tags covering various items, blocks, and fluids. Some of the most frequently used tags include:

forge:ingots: This tag is used for all types of ingots, such as iron, gold, copper, and modded ingots.
forge:ores: This tag is used for all types of ores, such as iron ore, gold ore, copper ore, and modded ores.
forge:logs: This tag is used for all types of wood logs.
forge:crops: This tag is used for all types of crops, such as wheat, carrots, potatoes, and beetroots.

Before creating a new tag, it’s essential to check if a suitable existing tag already exists. This can prevent duplication and ensure compatibility with other mods.

Forge Tag Types

It’s crucial to understand the different types of Forge tags available. The main types include:

Items: Tags that refer to Minecraft items, including both vanilla and modded items. These are commonly used in crafting recipes, loot tables, and advancements.
Blocks: Tags that refer to Minecraft blocks, including both vanilla and modded blocks. These are commonly used in world generation, structure definitions, and block-specific recipes.
Fluids: Tags that refer to Minecraft fluids, including both vanilla and modded fluids. These are used in fluid-based recipes and fluid handling systems.

Understanding the type of tag you need is essential for placing the tag file in the correct directory and using the tag effectively.

Using Forge Tags in Datapacks Crafting Recipe Example

Let’s illustrate the use of Forge tags with a practical example: creating a custom crafting recipe that accepts any iron ingot, regardless of its origin (vanilla or modded).

First, consider a vanilla crafting recipe that uses minecraft:iron_ingot:


{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "###",
    "# #",
    "###"
  ],
  "key": {
    "#": {
      "item": "minecraft:iron_ingot"
    }
  },
  "result": {
    "item": "minecraft:iron_block",
    "count": 1
  }
}

To make this recipe compatible with modded iron ingots, you would replace "minecraft:iron_ingot" with "#forge:ingots/iron":


{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "###",
    "# #",
    "###"
  ],
  "key": {
    "#": {
      "tag": "forge:ingots/iron"
    }
  },
  "result": {
    "item": "minecraft:iron_block",
    "count": 1
  }
}

By using the forge:ingots/iron tag, the recipe will now accept any item tagged as an iron ingot, providing seamless compatibility with mods that add new types of iron ingots. It changes item to tag because the recipe is now looking for a tag instead of a direct item.

Advancement Trigger Example

Another common use case is in advancements. Suppose you want to create an advancement that triggers when the player obtains any iron ore, regardless of whether it’s vanilla or modded.

The original trigger might look like this:


{
  "criteria": {
    "obtained_iron_ore": {
      "trigger": "minecraft:inventory_changed",
      "conditions": {
        "items": [
          {
            "item": "minecraft:iron_ore"
          }
        ]
      }
    }
  },
  "rewards": {
    "experience": 10
  }
}

To make this advancement compatible with modded iron ore, you would replace "minecraft:iron_ore" with "#forge:ores/iron":


{
  "criteria": {
    "obtained_iron_ore": {
      "trigger": "minecraft:inventory_changed",
      "conditions": {
        "items": [
          {
            "tag": "forge:ores/iron"
          }
        ]
      }
    }
  },
  "rewards": {
    "experience": 10
  }
}

Creating Your Own Forge Tags When Needed

Sometimes, existing Forge tags might not perfectly suit your needs. In such cases, you can create your own custom tags. This allows for highly specific and tailored item groupings.

To create a custom tag, you need to create a JSON file in the appropriate directory within your datapack. The file path should follow this structure: data/<namespace>/tags/items/<tag_name>.json (or blocks, fluids depending on the tag type). Replace <namespace> with your datapack’s name and <tag_name> with the name of your tag.

For example, if your datapack is called “mydatapack” and you want to create a tag called “special_ores”, the file path would be data/mydatapack/tags/items/special_ores.json.

The content of the file would look something like this:


{
  "replace": false,
  "values": [
    "minecraft:iron_ore",
    "mymod:super_ore"
  ]
}

This tag includes both vanilla iron ore and an ore from a mod called “mymod”. Now, you can use the #mydatapack:special_ores tag in your recipes, advancements, or loot tables.

Troubleshooting Common Tag Issues

Even with careful attention to detail, issues can arise when working with Forge tags. Here are some common problems and their solutions:

Tag Not Working?

Incorrect file path: Double-check that the tag file is located in the correct directory.
JSON syntax errors: Use a JSON validator to check for errors in the tag file.
Typos in item/block/fluid IDs: Carefully review the item IDs for any typos.
Incorrect namespace: Make sure you’re using the correct namespace for your datapack and any mods you’re referencing.
Replace flag: Is your replace flag accidentally set to true when you were planning on appending an item to the list?

Debugging Tips

Check Game Logs: Review the Minecraft game logs for any errors related to datapacks or Forge tags.
Datapack Validate Command: Use the /datapack validate command in-game to check your datapack for errors.

Conclusion

Forge tags are powerful tools that can significantly enhance the compatibility and flexibility of your datapacks. By understanding how to create, modify, and use Forge tags, you can seamlessly integrate modded content into your custom Minecraft experiences, ensuring your creations are enjoyed by all players, regardless of their mod configurations. So now you understand forge tags in datapacks, we hope you are able to go and create datapacks with no compatibility issues! Now get to datapacking and get those forge tags working.