How to Write a TTRPG Campaign (From Blank Page to Session One)

Writing a campaign from scratch is where most aspiring GMs stall. They have a world, maybe. A cool villain concept. A setting sketch. But translating those raw materials into something you can actually run — session one, session two, session ten — is the step that kills more campaigns than any other problem.

The block usually isn't imagination. It's structure. You don't know what you're supposed to write first, so you flail: you write backstory, then you write a villain, then you draw a map, then you realize none of it connects, and you start over. Weeks pass. You haven't run a session. Eventually you shelve the whole thing.

This guide is the writing process that gets you to a runnable session one in ten to fifteen hours of focused work. It separates the writing from the running — because they're different skills, and treating them the same is why campaigns fail before they start.

The Writing Sequence

Work in this order. Each step depends on the previous.

1. The thematic question
2. The opening situation
3. The antagonist and their goal
4. The cast (six key NPCs, three factions)
5. The world, just enough
6. The opening arc (sessions 1–5)
7. The hooks per PC
8. The session one outline

Skipping ahead is the most common failure mode. GMs who start with the world spend months on geography while the campaign itself never forms. GMs who start with the villain write an antagonist with no context. Start with the question.

Step 1: The Thematic Question

Every good campaign is about something — a question, a tension, a moral problem the players will be forced to answer through play. This question is the seed. Everything else grows from it.

A thematic question isn't a plot. It's a tension. Examples:

• What does loyalty mean when the thing you're loyal to is wrong?
• Can a kingdom be rebuilt, or does every rebuilding carry the seeds of the old collapse?
• Is the world worth saving if saving it means becoming what you hate?
• When the gods have abandoned people, what fills the space they leave?

Write three candidate questions. Pick the one that most excites you. If you don't care about the question, you won't carry the campaign through its slow middle. Your excitement is the fuel.

Once you have the question, you don't need to tell the players. They'll feel it through the scenes. What you need is to know it, so every design choice can be measured against it. When a scene doesn't serve the theme, cut it.

Step 2: The Opening Situation

The opening situation is the world's state when the campaign begins. Not the history. Not the full backstory. The now.

Describe in one paragraph: what just happened, what's currently happening, what's about to happen. A world in motion. The situation should have pressure — something is wrong, something is changing, someone is about to act.

Examples:

• "The old king has died three weeks ago. His heir is twelve. Three regional lords are moving their armies toward the capital. The kingdom has not been at peace with itself in six months, and nobody calls it a civil war yet."
• "The ancient barrier that kept the dead out of the realm has weakened over the past year. Nobody knows why. The bordering villages have started to see the first walking corpses. The mages' college insists there is no cause for alarm."

The situation should connect to your thematic question. If the theme is loyalty, the situation should put loyalty under stress. If the theme is rebuilding, something has just broken.

Step 3: The Antagonist and Their Goal

Your primary antagonist is the force pushing the situation toward bad outcomes. Not necessarily a single villain — could be a faction, a plague, a returning god — but a specific opposing force with a specific goal.

Answer, in detail:

• What is the antagonist's final goal — the state of the world they're moving toward?
• Why do they want it? (Not "evil" — an actual reason that makes sense to them.)
• How are they currently pursuing it? What are they doing this week, next month, this year?
• What happens if nobody stops them?

The last question is critical. A campaign without a visible timeline of failure lacks urgency. If your antagonist's victory is vague, the pressure dissipates. If "in six months, the barrier collapses entirely and the dead overrun the kingdom," now we have a ticking clock.

For writing villains specifically, see our guide to writing a memorable fantasy villain — it goes deeper on motivation, flaw, and presence.

Step 4: The Cast

Now people. A campaign needs roughly:

• The antagonist (you already have them)
• 2 allies — important NPCs on the party's side
• 2 neutrals — NPCs whose interests don't obviously align with anyone
• 1 rival — someone opposed to the party but not the main villain
• 3 factions — power centers in the world with their own agendas

For each NPC: a name, a one-paragraph description, what they want, what they know, what they fear.

For each faction: a name, a one-paragraph identity, their goal in the current situation, who leads them, and how the party might come into their orbit. Our faction system guide has a deeper template if you want one.

This cast is your world's beating heart. Every session, at least one of these people or factions should show up, make a move, or have their state change because of the party's actions. The world isn't passive — it's full of people with their own agendas, adjusting to what the PCs do.

Step 5: The World, Just Enough

Now you write the world — but only what's needed for the opening arc.

That includes:

• The region the party will operate in for the first 5–8 sessions (not the whole continent)
• 2–3 settlements with distinct feels and 3–5 NPCs each
• The landscape — terrain, weather, notable geography
• A rough sketch of broader world context: neighboring kingdoms, dominant religions, magical baseline

Resist the urge to write everything. Players explore outward from where they start; fill in more as the campaign moves. Worldbuilding you haven't been asked for is worldbuilding nobody will see.

For a deeper framework on building worlds efficiently, our campaign setting from scratch guide walks through how much world you actually need at each stage.

Step 6: The Opening Arc

The opening arc is sessions 1 through 5-ish. It needs to:

• Introduce the situation's pressure
• Get the party invested in the world and the question
• Show the antagonist's presence (without necessarily a direct confrontation)
• Set up the larger campaign

Structure it as 3–5 semi-standalone adventures linked by tonal and thematic thread. Each adventure should:

• Have a clear hook, conflict, and resolution
• Introduce 2–3 NPCs or one faction
• Touch on the thematic question
• Leave at least one thread that carries into later sessions

Don't write all five adventures in detail yet. Write session one fully. Sketch session two. Note the rough shape of the rest. The party will reshape your plans anyway; over-writing wastes the work.

Step 7: Hooks Per PC

Once the players make characters, this step completes itself. For each PC, design a personal hook — a tie into the opening situation that isn't just "adventuring is your profession."

• A family member in one of the factions
• A mentor who knows something about the antagonist
• A debt owed to one of the key NPCs
• A secret that ties them to the barrier / kingdom / dead
• A prophecy or premonition — use sparingly, but one per campaign is fine

Each PC should enter session one with at least one thread into the campaign's central mystery or conflict. This is what separates a party of these characters from a party of interchangeable adventurers. Our guide to handling player backstories goes deeper on the integration pattern.

Step 8: The Session One Outline

Finally, the detail work. Your session one outline:

• A vivid opening — somewhere in the middle of something happening
• The hook that brings the party together or activates them
• Three scenes that introduce key NPCs, factions, or situation beats
• A first meaningful choice
• A cliffhanger or question to end on

Write this as one page of bullet points. Not prose. Bullet points. You'll improvise the rest at the table; the bullet points are the skeleton that keeps you oriented.

Before session one: run a session zero with your group. Set expectations, create characters together, align on tone. Our session zero guide is the full checklist.

What You Write vs. What You Discover

Here's the key insight most new GMs miss: you're not writing the whole campaign. You're writing the conditions for the campaign, and the first chapter. The rest emerges in play.

What you write ahead of time:

• The theme
• The situation
• The antagonist
• The cast and their wants
• The opening region
• The first 3–5 adventures in sketch form
• Session one in detail

What you discover through play:

• What the party cares about
• Which NPCs become significant
• Which factions become central
• The specific shape of the antagonist's defeat
• The midpoint revelation
• The emotional arc of each character
• The ending

Writing only the pre-play half lets the campaign breathe. Writing all of it — every beat, every NPC, every ending — creates a campaign that feels dead because the players aren't in it, they're executing it.

When to Start Running

Start session one when you have:

• The thematic question
• The opening situation in one paragraph
• The antagonist and their six-month plan
• Six NPCs and three factions, each with wants and a one-line description
• Three settlements in your opening region
• A session one outline you could run tonight

You don't need more. More is overwriting. Your first session will teach you what you need to write for session two. That's the rhythm — write just enough to run, run, learn, write just enough again.

The Ongoing Writing Practice

Once the campaign is running, your writing time shifts from setup to maintenance:

• 1–2 hours between sessions writing the next session outline
• 30 minutes logging what the party did and what changed in the world
• Occasional deeper writing sessions when a new region, faction, or NPC enters play

Store all of this in one place — a campaign wiki, a linked notes setup, whatever works. Writing is only valuable if you can find what you wrote three months later when a player says "remember that merchant with the scar?"

The Trap of Over-Writing

Every aspiring GM I've talked to who abandoned a campaign before session one had the same symptom: they wrote too much, for too long, before running anything. They had 40 pages of lore, three maps, a pantheon, a calendar system, currency conversion charts — and no session one.

Write less. Run sooner. You'll learn more about your campaign in the first three sessions than in the previous three weeks of solo worldbuilding. Every hour of writing past session-one readiness is an hour that wasn't spent playing the game you wanted to make.

The ten-to-fifteen-hour campaign prep — theme, situation, antagonist, cast, opening arc, session one — is enough. It's more than enough. The best campaigns you'll ever run are the ones that were incomplete when they started and grew into themselves. Trust the process. Trust the table. Write the bones; play the flesh.