← Contents

Chapter 1

Introduction

You’ve felt it.

You know the feeling. A room that is always cold, even in the height of summer. A response to a question you only thought. The shadow that is too deep and you just know it is watching you. That moment when the veneer of ordinary stops sticking to reality and peels back a little. The world stops being real and you perceive the reality underneath the matte painting.

Those moments happen to everyone. Most people experience them, decide that they must be tired or imagining things and never look again. 20 Below is about people who look at the man behind the curtain - and what they can do once they have.

The rest of this book is how they do it.

What Is 20 Below?

20 Below is a tabletop roleplaying game. I’m sure you know what one is. I mean, you picked up this book.

What’s that? You don’t know what a TTRPG is? Well, allow me the pleasure of explaining it to you!

Simple explanation: a tabletop roleplaying game is like a game of make-believe. You remember running around as a kid - roaming the neighborhood with your friends. The stick you found in the woods was your sword, your wizard’s staff or laser rifle. Remember those epic arguments?

Kevin: I got you!
Mia: No. You didn’t!
Kevin: Yes, I did!
Mia: Nope. You missed!
Kevin: You always cheat! I quit!

A TTRPG is exactly like that, except when Kevin says, “I got you!”, there are rules in place so he can say, “I got you… honest.”

Complex explanation: at the core, any tabletop roleplaying game is an exercise in collaborative storytelling. The game master crafts a world, creates the characters you interact with and sets events in motion. The players decide how their characters react in every situation. It is a mutual dance of give and take that guides a shared universe and story. When anything is in doubt - a physical stunt, a mystic effect, deception or a fight - fate settles it.

In this case, fate is a pair of ten-sided dice. I know, it’s an underwhelming face for such a grand concept, but it’s what I’ve got. You roll the dice and add them together. Compare them to your target number. If you roll your target number or under, you succeed. Roll a 2 and you’ve done something people will talk about for years. Roll a 20 and you may never live it down.

Why You Roll What You Roll

That’s how you roll, but what do you roll and why?

Earth, Air, Fire, Water, Moira - the building blocks of the universe. These are the raw metaphysical materials that everything is made from - people, animals, the cosmos. All of it. This is the stuff running under the hood, governing everything that happens. Your Skills are what happens when you take one of these broad forces of the universe and hone it to a razor’s edge. The Elements are your potential. Your Skills are what you are actually good at.

Then there are Gifts. Gifts are the extraordinary abilities that the average person just doesn’t possess. Some call it magic, a knack, psionics, a blessing, mutations - whatever the flavor of your story calls for. The names change, but the structure never does. A Gift is a specific supernatural ability that is yours and yours alone. No two players will build their characters the same way.

Most TTRPGs have a setting - a world that the game is run in - baked right in. 20 Below is different in that it is “setting and design agnostic.” That is to say, it was designed to be an RPG system that can be used for any setting of any genre. 20 Below is the engine that propels the action, not the car.

The same Elements and dice will drive a haunted village, a generation ship in the depths of space, a war fought over machines that control the weather. Nothing under the hood changes when you switch from one setting to another. You craft the world, the system manages what happens within it. If you don’t feel up to making your own setting, my first campaign book - Backwater Static: a New Orleans floating on deep currents of weirdness - will always be free.

That is just one shape that 20 Below can take. There are many others. Most of them are yours.

What You Need to Play

It doesn’t take much:

That’s it. The whole exhaustive list. Hell, you don’t even need the dice - I built a free character creator that includes a built-in dice roller. Everything else - miniatures/tokens, maps, a GM screen - is optional.

How to Read This Book

I’ve made it as simple as possible to get into. You don’t need to read this book from cover to cover - almost no one does.

If you are a player, turn to the character creation chapter and work through the steps in order. Each step sends you to the chapter you need - Skills, Boons, Gifts, Flaws - exactly when you need it. You learn the game as you build your character.

If you are the GM, run through the character creation process once yourself. Then read the Combat section and get comfortable with the Difficulty Chart before Session Zero - those are the two things you’ll lean on most in play. (Unless you manage to write a campaign that eschews combat while still holding the table’s attention. It’s not easy to do, but it has been done.)

Everything else in the book is reference. Each chapter is a deep dive into one type of character option and is built to be opened mid-game and closed again a moment later. The Glossary at the front has everything you need to know going in and anything that only matters in a fight is in the Combat section.

Free. Always.

20 Below is and always will be free. The core rules (which you are reading now) will always be available to play - not a demo, not a simplified primer, not a trimmed down teaser - the whole system. Every rule in this book, the Character Creator, the desktop apps… all of them will always be free. I won’t release a second edition and make you pay for it. In fact, the apps are being designed so that they update as I refine the rules. In fact, as long as you have an internet connection, you will always have the most up to date ruleset.

Backwater Static - my first full setting - will also always be free, on the web and as a PDF.

Eventually, I will release things that aren’t free. The split is simple: the core game is always free; expansions will be paid add-ons.

These will be optional and never required to play the game.

Setting the Stage

Being setting and design agnostic, 20 Below can’t set the scene for you. It can’t give you the tone or feel for a campaign. As such, that is a conversation to have before anyone puts pen to paper. It doesn’t have to be a long talk, but it should be a real one.

The GM should walk the table through four things before anyone commits to a character.

Concept. The campaign in one sentence.

Goal. What the characters are here to do - win, survive, or just find out what happens. The whole table decides.

Tone. Pulp adventure? Slow-burn psychological thriller? Existential horror?

Subject matter. What belongs in this story and what doesn’t. Set the boundaries as a group, and talk about what happens off-screen.

Remember: 20 Below asks players to lean into their character’s worst moments. Their Flaws, bad luck and rolls that go wrong are far more interesting than getting everything you want. This is intentional and the system rewards them for it. This means that the conversation on tone does a lot more heavy lifting than in a lot of TTRPGs and it is meant to. This five minute conversation at the beginning can prevent a bad day at the table down the road.

A Word From the Designer

The opening paragraph - hell, the opening sentence - of every book is the hardest one to write. The opening sentence of my first novel took a decade. The suggestion for this section of the book was “give them one evocative paragraph, set the tone, don’t hit them with mechanics yet.” I gotta tell you - the moment someone tells you to be evocative, you lose the ability to be eloquent. So, instead, you get the inane ramblings about my obsession and passion project.

20 Below exists because I always wanted to do more with the games I loved. Either they had a system that was inextricably linked to the setting, or they were so generic that they felt like we were playing with Spooderman and Bortman. Don’t get me wrong, there are

a couple “generic” RPG systems that are fantastic, but they are super crunchy and math heavy. I wanted an engine that I could aim at any setting and it would just work.

That is why 20 Below is heavily inspired by anime. Anime has a depth and breadth of genres and settings that defies simple explanation, but is defined by broad tropes that can be seen in most of them. I wanted 20 Below to function a lot like that.

This all started out with a lot of big ideas. Most of them ended up filed down, polished, and refined into what you see here. Everything good about the system comes from someone telling me something was wrong or it didn’t work. And they were right. Stats got shuffled. Descriptors got overhauled fifteen times over. A status effect for characters pushed past their limit got cut. All of this made the game better.

All of that has been a hopelessly complex tangle and journey.

One part, however, was never complicated: it’s free because I want everyone to play.