D12 System

A simple, rules-light RPG system for Foundry Virtual Tabletop focused on storytelling and narrative gameplay using a d12 die mechanic.

Overview

The D12 System is a streamlined tabletop RPG system designed to get out of the way of your story. With a focus on quick resolution and flexible mechanics, D12 provides game masters and players with the tools they need to tell compelling stories without drowning in complex rules.

• Simple d12-based mechanics - Straightforward dice mechanics for resolution
• Six core abilities - Strength, Agility, Intelligence, Perception, Charisma
• Flexible defense system - A simple resolution system using three defense types: Armor, Endurance, Willpower
• Character and NPC support - Dedicated actor types for player characters and NPCs
• Item management - Support for equipment, spells, and other items
• Narrative-focused - Designed to support roleplay and storytelling first

1. Open Foundry VTT and navigate to Settings > Game Systems
2. Click Install System and search for "D12"
3. Select the system and click Install

Copy the following manifest URL into Foundry VTT's system installer:

https://raw.githubusercontent.com/foundryvtt-d12/d12/refs/heads/main/system.json

The D12 System uses six core abilities to represent character capabilities:

• Strength (STR) - Physical power and endurance
• Agility (AGI) - Speed, reflexes, and coordination
• Intelligence (INT) - Knowledge and reasoning
• Perception (PER) - Awareness and observation
• Charisma (CHA) - Force of personality and social influence

Characters can defend against threats using various defense types:

• Armor (ARM) - Physical protection
• Endurance (END) - Resistance to harm
• Willpower (WIL) - Mental resistance
• Fixed DC - Static difficulty class for specific challenges

Player characters have full ability and defense stats, inventory management, and spell tracking capabilities.

Non-player characters use the same character sheet but are designed for quick NPC management.

The character sheet provides:

• Ability scores and modifiers
• Defense stats
• Health and mana tracking
• Inventory management
• Spell list

Create and manage:

• Equipment - Weapons, armor, and other gear
• Spells - Magical abilities and effects
• Items - General inventory items

For issues, questions, or feature requests, please visit the GitHub Issues page.

MIT License

Copyright (c) 2025 Flavien Charlon

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

• Flavien Charlon - Creator and maintainer