Background

Introduction

This is a campaign for one young player and one Games Master, in the real stellar neighbourhood, where the only way between stars is a child walking through a door.

It is built to be somebody’s first roleplaying game. That shapes everything: there are no pre-made characters, the first session is deliberately light, the rules are Mythras Imperative unmodified and run in the open, and the setting explains itself by being lived in rather than by being read.

If you have run anything before you will find nothing strange here. If you have not, the one thing to know is that this campaign has an opinion about what makes a young player’s first game good, and the opinion is in the fourth part of this book.

What you need at the table

This book is a scenario and a setting. It is not a rules system, and it does not contain one. There are statistics all through it — characteristics, skill values, passions, combat styles — and every one of them assumes a set of rules that lives somewhere else.

Which set depends on how you intend to run it, and there are two honest answers.

Running it with the engine

Claude plus the mythras-gm plugin. The rules are implemented in code: it rolls, applies the difficulty grade, resolves everything, and tells you what happened. You can sit down and play tonight without having read a rulebook, and the first session teaches the system by using it.

Running it yourself

A person at the head of a table, with dice. Then you need a copy of Mythras Imperative, and you need it before you start. Nothing in this book will teach you how to resolve an action. What a difficulty grade does to a skill, how an opposed roll is won, what a special effect is and when somebody earns one, how damage lands on a hit location, what a Luck Point may be spent on — all of that is in the rules, and none of it is in here.

It is free. Mythras Imperative is The Design Mechanism’s own cut-down edition of Mythras — a complete game, not a demo — and they publish the PDF at no cost on their free downloads page, under the ORC License, with permission to pass it on. Everything here was written against Imperative and is run against Imperative unmodified. Nothing in this campaign needs anything beyond it.

If You Have Never Run a Game Before

Which, for this campaign, is likely. It is written for a ten- to fifteen-year-old, and the person most likely to be sitting opposite them is a parent who has never done this and is not certain they can.

You can. Here is the honest shape of it.

What you actually have to read. Imperative is about sixty pages. To start you need perhaps fifteen of them: how a skill roll works, the difficulty grades, criticals and fumbles, and Luck Points. That is one unhurried evening, and the Players’ Guide chapter How the Dice Work is the same material in two pages if you want the shape of it first.

You can skip combat entirely. Combat is the part of Mythras that looks frightening to a new Games Master — hit locations, special effects, opposed rolls — and it is genuinely the most detailed thing in the system.

There is no fighting anywhere in this campaign. Not one beat of it. The danger here is physics and arithmetic and a clock: a door that will not open, a number that is rising, sixty-one people and not enough time. Nobody draws a weapon, because in this setting almost nobody ever does — a thing that reliably kills a person reliably opens a wall, and everybody lives inside a hull. So you may leave the combat chapter unread until the day somebody picks a fight, and in Act One nobody does.

The hardest thing is not the rules. It is the fourth part of this book — handing back where there is something to do, not performing finished scenes at your player, not putting words in their character’s mouth. That is a craft and it takes a few sessions, and every lesson in it was learned by getting it wrong at a real table.

Play it yourself before you run it. With the engine, as a player, start to finish. Three evenings is what Act One took the first time it was played, and it is better preparation than any amount of reading this book, because afterwards the book is a reminder of somewhere you have been rather than a description of somewhere you have not. You will also get your first bad crossing out of the way privately. Then run it for your player, and let their run be theirs — the thing you bring back from your own is the feel of it, never a route you are hoping they take.

And the rules being honest is on your side. The difficulty grade is declared before the dice fall, the dice are rolled in the open, and the answer is the answer. You never have to decide whether somebody succeeds. You decide how hard a thing is, and then you both find out — which is a much easier job than the one people imagine when they picture running a game.

If you take to it, buy the full Mythras. It is one of the best d100 systems anybody has written, the people who wrote it are still writing, and a campaign published free on top of somebody else’s free rules only works as an arrangement if some of us pay them.

A note on what the player needs: nothing. The Players’ Guide chapter on the dice is sufficient for somebody sitting at your table, and a first-time player should not be handed a rulebook.

The three design rules

Every act takes something. A loss that does not come back. An act in which the player only gains has not happened.

Ordinary world first. The player has to love the Nine before it is threatened. The hardest scene in Act One is the fourth beat, not the first.

Conditions accelerate; time backstops. A beat’s clock entry is the latest it can happen, not the earliest.

Danger, and the promise that replaces safety

People in this campaign can die, including the player’s character. The rules are not modified and nothing is softened behind the screen.

What the campaign promises instead is information. A character can only die from a risk that was named, in the fiction, before the player chose it. No unannounced trap, no ambush from a direction they had no way to check, and an honest answer every single time they ask whether something can kill them.

That is a duty on you, and it is the single most load-bearing thing in this book. It is written out at length in TABLE-ADDENDUM.md, which you should read before you run anything.

It also pays for itself. A young player who learns that asking produces a real answer asks constantly, and a player who asks constantly is a player who is playing rather than waiting.

The astronomy is real

Every system, star type, planet, distance and oddity in this campaign is a real, current measurement, cited in the source files. data/systems.json is the authority and there is a test enforcing it. If the prose and the data ever disagree, the data wins and the prose is the bug.

Invented life is the one exception, and it is constrained to genuinely unobserved surfaces, consistent with the real system’s temperature and insolation, and flagged where it occurs.

Do not write a figure from memory at the table. Look it up. Being able to say that is a real star and here is what we actually know about it is a large part of what this campaign is for.

The proof of all that is the chart in the next chapter but one. It is drawn from the data rather than by eye, and on screen every star name on it is a link to that star’s own Wikipedia article — so a player who does not believe you can go and check, at the table, in about four seconds.

How to read this book

The first part is what is going on and why, including the ending. The second is the station and everybody on it. The third is Act One, beat by beat — that is the part you need to run next week. The fourth is table craft, and it is the part that is specific to running for a young player, and it is short because the lessons in it were expensive.