How To Make A New Effect Foundry

7 min read Oct 10, 2024

How to Make a New Effect in Foundry VTT

Foundry VTT is a powerful and versatile virtual tabletop platform that allows you to create and run tabletop role-playing games digitally. One of its key features is the ability to create custom effects, enhancing your game's visual and thematic elements. Let's explore the steps involved in creating a new effect for Foundry VTT.

Understanding the Basics

Before diving into the technical aspects, it's important to grasp the fundamental concepts:

Effects: Foundry VTT effects are visual elements that can be applied to tokens, actors, or the game world itself. They can add animations, status icons, lighting changes, and more.
Foundry VTT's System: Foundry VTT utilizes a modular system where custom effects can be created through the use of JavaScript code and the platform's API.

Steps to Create a New Effect

Choose an Effect Type: Foundry VTT offers various effect types, each catering to specific visual and functional needs:
- Token Effect: Applies to individual tokens, affecting their appearance, behavior, or status.
- Actor Effect: Targets specific actors, granting them temporary abilities, debuffs, or visual changes.
- Scene Effect: Modifies the game environment, introducing dynamic lighting, weather effects, or atmospheric elements.
- Custom Effect: A versatile type allowing you to create unique and complex effects with custom code.
Script Your Effect: The core of your new effect lies in the JavaScript code that defines its behavior. Here's a breakdown of the process:
- Create a New Module: Foundry VTT modules are self-contained units where you can store your effect scripts and configurations.
- Implement the Effect Logic: Within the module's script, you'll define the effect's actions, such as:
  - Appearance: Customize visual aspects like color, animation, icon, and duration.
  - Functionality: Implement specific effects, such as applying temporary bonuses, penalties, or triggering game events.
  - Triggering: Determine when the effect should be activated, e.g., on token creation, actor action, or specific game events.
Utilize the Foundry VTT API: The API provides a wealth of tools for controlling game elements and interacting with the system. Utilize these methods for your effect's logic:
- Token Manipulation: Modify token attributes, position, or appearance.
- Actor Modification: Adjust actor statistics, abilities, or conditions.
- Scene Interaction: Change lighting, weather, or other environmental features.
- Game Events: Trigger specific events within the game, such as dice rolls, sound effects, or chat messages.
Test Your Effect: Once the script is complete, thoroughly test your new effect within a Foundry VTT game. Verify its visual appearance, intended functionality, and compatibility with the game system you're using.
Share Your Creation: If you've created a unique and useful effect, consider sharing it with the Foundry VTT community. You can publish your module on the Foundry VTT marketplace or share it with friends and fellow players.

Example: Creating a "Blindness" Effect

Here's a basic example of creating a "Blindness" effect for a token:

// This script adds a "Blindness" effect to a token

const BlindnessEffect = {
    icon: "icons/sundries/eyes/eye-blind.webp", // Icon for the effect
    label: "Blindness", // Name of the effect
    duration: { rounds: 3 }, // Effect duration in rounds
    changes: [
        { key: "system.attributes.vision.value", mode: CONST.ACTIVE_EFFECT_MODES.CUSTOM, value: -10 }, // Reduce vision by 10
    ]
};

Hooks.on("createToken", (token) => {
    token.createEmbeddedDocuments("ActiveEffect", [BlindnessEffect]);
});

This code creates an effect named "Blindness" that reduces a token's vision by 10 for three rounds.

Tips for Creating Effects

Start Simple: Begin with basic effects and gradually increase complexity as you gain experience.
Utilize Existing Modules: Explore the vast library of available Foundry VTT modules for inspiration and ready-made solutions.
Leverage the Community: Seek help and guidance from the Foundry VTT community forums and Discord channels.

Conclusion

Creating custom effects in Foundry VTT is a powerful way to enhance your game experience and bring your imagination to life. By understanding the fundamentals and leveraging the platform's API, you can create effects that add visual flair, strategic depth, and a unique touch to your virtual tabletop adventures.