What is the main purpose of the fvtt-active-effects skill?

It helps developers correctly implement and manage Active Effects in Foundry VTT, covering everything from basic attribute modifiers to complex custom logic hooks.

Why should I use this instead of standard JavaScript coding?

This skill understands the specific Foundry VTT lifecycle, such as the prepareData execution order, preventing common errors like targeting derived values instead of base data.

Does this support both Legacy and Modern effect transferral?

Yes, it provides guidance and code patterns for both legacy copy-on-embed behavior and the modern CONFIG.ActiveEffect.legacyTransferral = false approach.

Can this skill help with complex combat-based durations?

Absolutely. It includes patterns for tracking durations across world time, combat rounds, and specific turns to ensure buffs expire exactly when intended.

Foundry VTT Active Effects Manager

Name: Foundry VTT Active Effects Manager
Author: ImproperSubset

byImproperSubset

Game Development

Implements and manages Foundry VTT Active Effects for dynamic actor attribute modifications, status conditions, and equipment bonuses.

About

This skill provides specialized guidance for Foundry Virtual Tabletop (VTT) developers working with the Active Effects system. It facilitates the creation of complex buffs, debuffs, and item-based stat modifications by ensuring correct implementation of effect modes, timing within the data preparation cycle, and advanced custom logic. Whether you are building a new game system or a complex module, this skill helps navigate the nuances of duration tracking, effect transferral, and data path targeting to prevent common pitfalls like targeting derived values or incorrect initialization.

Key Features

0 GitHub stars
Automated ActiveEffect structure generation for systems and modules
Expert guidance on Active Effect Modes including ADD, MULTIPLY, and OVERRIDE
Best practices for effect timing within prepareBaseData and prepareDerivedData
Advanced CUSTOM mode implementation using system hooks for complex logic
Duration management for world-time clocks and combat-based round tracking

Use Cases

Implementing spell-based buffs and debuffs with automatic expiration tracking
Building status conditions like Prone or Stunned that apply specific mechanical penalties
Creating equipment bonuses that dynamically modify actor armor class or movement speed

About

Key Features

0 GitHub stars
Automated ActiveEffect structure generation for systems and modules
Expert guidance on Active Effect Modes including ADD, MULTIPLY, and OVERRIDE
Best practices for effect timing within prepareBaseData and prepareDerivedData
Advanced CUSTOM mode implementation using system hooks for complex logic
Duration management for world-time clocks and combat-based round tracking

Use Cases

Implementing spell-based buffs and debuffs with automatic expiration tracking
Building status conditions like Prone or Stunned that apply specific mechanical penalties
Creating equipment bonuses that dynamically modify actor armor class or movement speed