Adventurer Conqueror King System

Latest version0.9.2
Minimum Core9.0
Compatible Core9.269
Last updated2 years ago
Created3 years ago
Languages English
French (FRANCE)
Português (Brasil)
Systems All systems
Project source Project URL

Adventurer Conqueror King System for Foundry VTT

This game system for Foundry Virtual Tabletop provides character sheet and game system support for the Adventurer Conqueror King System (ACKS).

This system provides mechanics and character sheet support, and features a compendium with Monsters, Items, Spells, Proficiencies and Abilities, and more, all to make the judge's job easier for running ACKS games on the Foundry VTT. Also included is a world map of the Auran Empire (the default setting of ACKS) - although the judge is free to ignore it. Every campaign is a law unto itself.

ACKS, like most B/X clones, is also broadly compatible with thousands of modules and other OSR content and rulesets with a minimum of conversion necessary.

ACKS for Foundry VTT Features

Core Rules

  • ACKS encumbrance rules (using coin weight instead of stone - 1000 coins to a stone)
  • ACKS Armor Class (Ascending starting from 0)
  • Uncapped dexterity and charisma bonuses
  • Exploration checks (hear noise, open door, etc) are 1d20 skill checks
  • Tweak section of the character sheet to modify throws, AC, etc for proficiencies or class bonuses
  • "Slow Weapon" checkbox on items to subtract 1 from an actor's initiative if equipped
  • HOLD TURN icon in the Combat Tracker to remind the judge that a player has held their action
  • Encumbrance bar to reflect movement rates while encumbered
  • Pre-programmed saving throws for monsters based on HD
  • Auran setting languages in addition to standard tongues
  • Morale and Loyalty tracking for Henchmen
  • The ACKS Compendium has the majority of equipment, proficiencies, and spells from the Core Book. (Soon to have tables and core bestiary)
  • ACKS Repetoire-style casting
  • ACKS Core Treasure Tables
  • ACKS Investment Vagaries from AXIOMS

Heroic Fantasy Handbook (optional)

  • Added an option to use exploding 20s in combat
  • Added an option to add Basic Healing Rate to the character sheet
  • Added an option to apply wisdom bonus to all saves

Manual Installation

To install and use this system, simply paste the following URL into the Install System dialog on the Setup menu of the application.

If you wish to manually install the system, you must clone or extract it into the foundry "/data/systems/acks" folder. You may do this by cloning the repository /src folder or downloading and extracting the zip archive available on the GitHub page.

Community Contribution

Code and content contributions are accepted. Please feel free to submit issues to the issue tracker or submit merge requests for code changes. Approval for such requests involves code and (if necessary) design review by The Happy Anarchist. Please reach out on the Autarch Discord ("vtt-collaboration" channel) with any questions.

Big thank you to Bobloblah for laying the foundation of the ACKS compendium! He put in an enormous effort, all to save judges tons of work in getting their campaigns started.

Thank you to Olle Skogren for contributing the Investment Vagary tables from AXIOMS 3.

HUGE Mega-Thank you to Azarvel for his exhaustive work updating to Foundry v9.



This system is offered and may be used under the terms of the Open Game License v1.0a and the Adventurer Conqueror King Product Identity License v1.0. Permission to develop and distribute the ACKS system for Foundry, and to create and distribute the content in the compendium have been granted by Autarch LLC.

This code is modified from a fork of the v1.0 code of the Old School Essentials System written by U~Man, and released under the GNUv3 license. The software source of this system is also distributed under the GNUv3 license and is considered open source.

Autarch, Adventurer Conqueror King, Adventurer Conqueror King System, and ACKS are trademarks of Autarch LLC. You may find further information about the system at


Weapon quality icons, and the Treasure chest are from Rexxard, and came with the Old School Essentials System for Foundry VTT (Unofficial) by U~man which can be found at Other icons used in the compendium are distributed under the Creative Commons 3.0 BY license and are available on A list of icon authors and contributors for that project can be found on the website, or at Monster Tokens in the bundled ACKS Monsters Compendium are from the Free Token pack from Devin's Token Site and are made by Devin Night Other icons in the compendium are by Bobloblah or The Happy Anarchist. Map of the Auran Empire (default setting of ACKS) by The Happy Anarchist.

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