How do I include actor attributes in a roll formula?

Use the @ syntax within the formula string (e.g., '@abilities.str.mod') and provide the actor's getRollData() object as the second argument to the Roll constructor.

Is it safe to use raw user input in Roll formulas?

It is best practice to validate user-provided formulas using Roll.validate(userInput) before attempting to construct or evaluate a Roll object to prevent errors.

How do I respect the user's current roll mode (Public, GM, Blind)?

You should pass game.settings.get('core', 'rollMode') into the options object of the roll.toMessage() method to ensure privacy settings are honored.

Can I create custom dice types for unique game systems?

Yes, you can extend the Die class to define custom logic and register your new term in CONFIG.Dice.terms, allowing for new denominations like '1ds'.

Why do I need to await roll.evaluate() in Foundry VTT?

Foundry VTT's Roll.evaluate() is an asynchronous operation. The roll.total and roll.result properties remain undefined until the evaluation is complete and awaited.

Foundry VTT Dice & Rolls

Name: Foundry VTT Dice & Rolls
Author: ImproperSubset

byImproperSubset

Desarrollo de Videojuegos

Implements and manages complex dice rolling mechanics, formulas, and chat integration for Foundry VTT system and module development.

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The fvtt-dice-rolls skill provides expert guidance on the Foundry VTT Roll API, enabling developers to build robust game mechanics within the VTT environment. It covers the entire lifecycle of a roll—from constructing complex formulas with variable substitution to asynchronous evaluation and rendering results in chat. The skill includes best practices for actor/item data preparation via getRollData(), handling advanced modifiers like advantage/disadvantage, and implementing custom dice types to support diverse tabletop RPG systems.

Características Principales

Integration with ChatMessage and Roll Modes (GM, Blind, Self)
Implementation of custom Die and Roll classes
Advanced dice modifiers like keep/drop, exploding, and rerolling
Dynamic formula construction with @variable substitution
0 GitHub stars
Asynchronous roll evaluation and result handling

Casos de Uso

Adding rollable buttons to actor and item sheets with proper data context
Implementing specialized dice mechanics like stress dice or success-counting systems
Creating an automated attack and damage system for a custom TTRPG

Acerca de

Características Principales

Integration with ChatMessage and Roll Modes (GM, Blind, Self)
Implementation of custom Die and Roll classes
Advanced dice modifiers like keep/drop, exploding, and rerolling
Dynamic formula construction with @variable substitution
0 GitHub stars
Asynchronous roll evaluation and result handling

Casos de Uso

Adding rollable buttons to actor and item sheets with proper data context
Implementing specialized dice mechanics like stress dice or success-counting systems
Creating an automated attack and damage system for a custom TTRPG