How to Prep a One-Shot in Under an Hour

One-shots are one of the best formats in tabletop RPGs. No long-term commitment, no sprawling campaign notes — just a tight, satisfying story that begins and ends in a single session. The catch? A lot of GMs over-prep them. They treat a one-shot like a mini-campaign and end up with three hours of material for a two-hour slot. Here's a framework that keeps prep lean and the session sharp. ## The One-Shot Formula Every great one-shot has three things: 1. **A clear goal** — something the players need to accomplish 2. **A ticking clock** — a reason they can't wait around 3. **One meaningful choice** — a moment where the players decide what kind of people they are That's it. Everything else is decoration. ## Step 1: Write the Hook (5 minutes) Your hook is the one sentence that gets players into the action. It should answer: *What do the players need to do, and why now?* Examples: - "A merchant's daughter has been taken by bandits. The ransom deadline is dawn." - "A wizard's tower has appeared overnight. The village elder wants it gone before the festival." - "The last ferry off the island leaves in three hours. Something is hunting the passengers." Notice each hook has a goal and a clock built in. That's the work done. ## Step 2: Build Three Scenes (20 minutes) One-shots don't need elaborate dungeons or branching paths. They need three scenes: - **Scene 1: The Setup** — Players learn the situation and make their first decision. - **Scene 2: The Complication** — Something goes wrong, or the situation is more complex than it appeared. - **Scene 3: The Climax** — The players face the central challenge and resolve it. For each scene, write one sentence describing what's happening, one interesting NPC or obstacle, and one way the players might interact with it. That's your prep. ## Step 3: Prep Two NPCs (15 minutes) You don't need a cast of dozens. You need two NPCs: - **The Ally** — Someone who helps the players and has a personal stake in the outcome. - **The Antagonist** — Someone who opposes the players, with a reason that makes sense. For each, write their name, their goal, and one memorable detail (a nervous habit, a distinctive voice, something they always say). That's enough to play them convincingly for a full session. ## Step 4: Pick Your Ending (10 minutes) One-shots need a satisfying ending, and the best endings come from the players' choices. Before the session, decide: - What does success look like? - What does failure look like? - What's the one moment where the players' decision changes the outcome? You don't need to script the ending — just know what's at stake when you get there. ## Step 5: Gather Your Tools (10 minutes) Pull together whatever you need at the table: a map if you're using one, any stat blocks for enemies, and a short list of names to use for improvised NPCs. Keep it to one page. --- That's an hour of prep for a session your players will remember. The framework works because it focuses your energy on what actually matters: a clear goal, a reason to act now, and a moment that means something. Ready to run your best one-shot yet? [Check out the full GM Tips series](/lp/gm-tips-series?utm_source=blog-aab&utm_medium=blog&utm_campaign=cmp_p4OjOaaH3eJQRXLEcl1OL50mYrsbu5nX0R_Rf4oK2Co&utm_content=act_Cs1LWUYGGVsk1zXIfYGdsTRYl-LZnmoOEWozx5gm9HY&utm_term=topic_one-shot-prep) for more practical guides built for GMs who want to run great games without burning out on prep.