Creating Rule System Modules, Adventures, and other GM Aid Addon Content

This tutorial series is being created in real-time and there will likely be typos as well as incomplete or missing elements as new articles get added to it. This will get revised and cleaned up while this is constructed.


The following is a step-by-step walkthrough on how to create Module and Addon content for sale on the Roll20 Marketplace. This can be a conversion of your print/PDF TTRPG Adventure or Rule Systems or content you build directly for the VTT.

What are the General Customer Expectations of Roll20 Marketplace Conversions of For-Print Products?

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The conversion of traditional for-print TTRPG media can take various forms on the Roll20 Marketplace.

  • Rule System Compendiums: A Roll20 Compendium takes the entire text of a rulebook and converts it into searchable data that can be browsed within the VTT itself as well as on-site. Compendium builds currently require Roll20 staff and/or vetted third-party freelance contractors who can build them for you. Additionally, we recommend that you also own the development rights of a Roll20 character sheet built for your rule system so that the Compendium can correctly interact with the sheet for drag-and-drop capability within the VTT. For more information on Compendium building, [go here].

  • Rule System Modules and Splatbook Addons: When a Compendium build isn't viable, the next best thing is creating a Game Module/Addon that includes all your systems rules, statted monsters, custom characters with classes, abilities, items, macros, rollable tables, and anything else included in the game template under their respective VTT elements. Just like Compendiums, we highly recommend you also own the development rights of a Roll20 character sheet built for the rule system you are selling. 

  • Game Adventure Module & Addons: This takes an Adventure Campaign and converts everything over into a Roll20 game so that a Customer can play it immediately. This includes:
    • The entire campaign's text converted over to Journal Handouts
    • All maps are included on their respective Pages on the Page Toolbar with GM Notes hidden from the players' view, all monster Tokens are placed where they need to be on the map, and Dynamic Lighting should be set up where it can be capitalized.
    • All monsters and NPCs required within the Adventure have Journal Character entries with filled-out character sheets and linked Tokens.
    • Rollable Tables such as random encounters tables, loot tables, and shapeshifting token/map art should be included if the table will be used more than twice.

  • GM Aid Addons: These are smaller game components that can be designed for a particular system in mind or be completely system agonistic. Some examples (but not limited to) are:
    • Custom Card Decks (critical success/failure decks, random magic, story prompts)
    • Dynamically Lit maps
    • Page dashboard elements such as counters or clocks
    • Locale write-ups
    • Preset encounter maps
    • Randomized tables (text and art versions)
    • Soundtracks
    • Inventory items

  • Art Packs: These items are pretty straightforward. These are collections of art assets used for various purposes such as battle maps, world maps, tile sets, tokens, handout images, cards, etc. These can be set to be downloadable by the customer if desired.

For the purposes of this guide, we'll be walking through the creation of Module and Addon content.

Module and Addon Overview

Modules and Addons are game templates that get added to a game where your print media has been converted over so it's ready to play on Roll20. The creation process of both is identical: you create a Roll20 game on your Publisher Roll20 account and start adding your content to it. The only difference between Modules and Addons is how they are installed in a Customer's game.

Modules can ONLY be added when the Customer first creates their game. These are best used for large chunks of content such as rulebooks, long adventure campaigns, or other situations where the template is expected to be a very standalone product.

An Addon can be installed at ANY time once the game has been created. You are also not limited to how many Addons that can be installed in a single game. These are best used for short or one-shot Adventures, smaller non-Compendium rule system Addons, and other GM Aids (card decks, rollable tables, encounters, etc)

What Can't You Use in a Module/Addon?

Nearly all of the available VTT elements that are available in the VTT can be used for a Marketplace Module or Addon. If it makes sense to use them for your content conversion, please do so.

The following are VTT elements that do not carry over when the Module or Addon template is uploaded to the Marketplace

  • Uploaded PDFs
  • Compendiums
  • Token Actions (macros set on the Token itself do not copy over with Addons, but do with Modules)
  • The Game's Chatlog
  • Installed Token Markers
  • "My Settings" tab settings

The Module/Addon Building Guide

Below is the recommended order of tasks you should follow when assembling your Marketplace Adventure:

Step 1: Getting Started

Step 2: Setting Up Your Map Pages

Step 3: Import Your Adventure Text

  • Creating Character entries
  • Creating Handout Entries
  • Organizing your Journal
  • Linking Journal Entries

Step 4: Setting up Tokens

  • Create a Token Page
  • Token Settings
  • Linking Tokens to Characters

Step 5: Setting up Rollable Tables, Card Decks, and Macros (when applicable)

  • Create Rollable Tables and Rollable Table Tokens
  • Create Custom Card Decks
  • Setting up Macros and Token Actions

Step 6: Reviewing your Adventure

  • Visibility in Dark Mode and Light Mode
  • Macro testing
  • Testing Dynamic Lighting

Step 7: Creating Your Marketplace Listing and Submitting it for Approval

  • Fixing Broken Images
  • Patches
    Step 1 - Create the Game Template >>
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