Get your table playing in minutes, not hours.
GATEWAY RPG is a free, rules-lite d20 system built for zero-prep adventures, sudden one-shots, and seamless intro sessions. Familiar 5E-style mechanics with all the bloat stripped out, so you can run any genre instantly: neon-soaked cyberpunk streets, grit-filled noir alleys, high fantasy, cosmic horror, and everything in between.
The Definitive Edition is now the main book. This is the complete, current version of GATEWAY RPG: updated core rules, solo play, a starter bestiary, and homebrew variants, character sheets all combined into one source. New artwork, professional layout, and everything players and GMs need in a single 132 page PDF.
Want the history? Every older version of the rulebook, spanning 2017 to 2026, is bundled in the Legacy Zip below for collectors and the curious. Download the complete PDF bundle.
AI Disclosure: This
Enhanced Edition of Gateway RPG features some AI-generated artwork and layout assistance. The rules were still hand written by me and human proofread/playtested since 2017. As a one-man passion project with
$0 budget, and
$0 revenue gain from this game, this edition utilizes AI imagery only to provide a visually richer and cohesive experience while keeping the game entirely FREE. The original Classic Edition from 2017, featuring human-created artwork, is included as a bonus in the download files. However, if you are only looking for a gaming experience completely free of AI-generated assets, the standalone
Classic Edition can be found exclusively on its own dedicated product page at
https://gatewayrpg.itch.io/gateway-rpg-classic-edition 
https://gatewayrpg.itch.io/gateway-rpg-classic-edition.
What’s Inside?
Definitive Edition (Main Book): The complete game in one volume. Updated rules, solo play engine, starter bestiary, and homebrew variants.
Legacy Zipfile (2017-2026): Every prior version of the rulebook, character sheet, supplement preserved as released. For archivists, returning players, and anyone who wants to see how the game evolved.
Core Rules: The streamlined engine for players and Game Masters, in both English and Spanish (Reglas en Español).
Character Sheets: Multiple Printable and Form Fillable Character Sheets
Ready-to-Play Content: Pregenerated characters and one-shot adventure modules spanning multiple genres. Jump straight into the action.
Player's Toolkit: Printable and form-fillable character sheets, a one-page quick reference guide, and the d20 Oracle for solo play.
Starter Bestiary: 25 adversaries across 11 settings, from High Fantasy to Space Opera to Lovecraftian Horror.
Homebrew Variants: Over 20 pages of optional mechanics, including Spark of Heroism (Inspiration), Pushing for Success (partial success), and genre modifiers for Survival and Cosmic Horror.
Pocket Character Sheets: Compact sheets designed for portability.
Solo Play Quickstart Zine: A portable, zine-style guide for on-the-go solo adventures.
NEW: Android Player Companion App
Character Builder: Create custom characters or select from 30 curated pre-mades.
Pocket Rules: Quickly search core mechanics and references on the fly. Sheet-Integrated
Dice: Roll checks directly from your sheet.
Solo Engine: Built-in oracle for quick, on-the-go solo adventures.
https://play.google.com/store/apps/details?id=com.aistudio.gatewayrpg.app
Designer's Note: GATEWAY RPG grew out of a personal passion for tabletop gaming. Back in 2015, I discovered S. John Ross’s classic 1993 game, Risus: The Anything RPG. It was free, modular, ultra-flexible, and simple to pick up, but as I played more TTRPG's like DND5e, I missed the iconic d20 and the drama of critical hits and misses.
I created GATEWAY RPG to capture that same beginner-friendly spirit while bringing back the thrill of the twenty-sided die and being able to use it for any setting. Whether you are running quick one-shots, playing standalone adventures, diving into solo sessions, or modularly introducing advanced rules as your group learns, GATEWAY adapts seamlessly to your table.
GATEWAY RPG and Aurican's Lair are a Not-For-Profit Tabletop Roleplaying Game publisher.