The Art of Improvisation: Running a Session Without Prep

Dear Readers,

Every Dungeon Master (DM) has been there: it's game night, and for one reason or another, you haven't prepped a single thing. Maybe life got in the way, maybe you thought you’d have more time, or maybe you just want to challenge yourself to see if you can run an entirely improvised session. Whatever the case, you’re staring down the barrel of an unprepared session, and your players are looking to you for adventure. So how do you run a fantastic game with zero prep? Welcome to the art of improvisation.

The Mindset of an Improvisational DM

Before we get into techniques, it’s important to set the right mindset. Running an improv-heavy session isn’t about floundering through random encounters or cobbling together something barely coherent. It’s about trusting yourself, your players, and the narrative tools you already have at your disposal. The key elements to keep in mind are:

• Confidence: Even if you’re unsure, present information with certainty. Your players will take their cues from you, so if you act like you know what you’re doing, they’ll believe it.
• Flexibility: Don’t cling to a rigid idea—let the story flow naturally based on player choices.
• Collaboration: Your players are a goldmine of ideas—use them! The game isn’t just about you spinning a tale; it’s about weaving a story together.

Core Techniques for Running an Unprepared Session

1. Leverage Your Players

One of the best tools in your arsenal is your players themselves. Ask them leading questions to build the world collaboratively:

• “You’ve been tracking this enemy for days—what clue led you to this abandoned village?”
• “This tavern seems familiar to you—why?”
• “What’s the most dangerous rumor you’ve heard about this region?”

Not only do these questions shift some of the world-building onto the players, but they also give them agency in shaping the narrative. A player-invested world is one they’ll care more about.

2. The Three-Pillar Rule

When in doubt, remember that D&D is based around three pillars: Exploration, Social Interaction, and Combat. If you’re unsure of what to do next, simply pick one and build a scene around it:

• Exploration: The party stumbles upon a strange ruin in the forest, an unmarked cave, or a mysterious landmark with ancient carvings.
• Social Interaction: A distressed NPC approaches them with a desperate plea for help, a merchant offers a too-good-to-be-true deal, or an old rival resurfaces.
• Combat: They’re ambushed by bandits, attacked by a local predator, or forced into a duel by an insulted noble.

Simply thinking in terms of these three categories can help you structure an engaging session on the fly.

3. Recycle and Reskin

If you’re truly caught off guard, don’t hesitate to recycle old ideas. Have a dungeon you ran months ago that players never finished exploring? Bring it back under a different guise. Need a villain? Modify an existing NPC from an earlier arc. Players have an amazing ability to take things at face value, so don’t be afraid to repurpose assets.

Similarly, reskinning monsters, locations, and encounters can save a ton of time. Need a quick monster but don’t have stats on hand? Grab something from the Monster Manual and reimagine it:

• A ghost becomes a shimmering figure from a failed magical experiment.
• A mimic becomes a cursed artifact that shifts form when touched.
• A gnoll pack becomes a group of bandits infected with lycanthropy.

4. The Rule of Three

The Rule of Three is a simple but effective improvisation tool. Whenever you introduce something new—a location, an NPC, a conflict—give yourself three quick details to anchor it in your mind and flesh it out:

• The Spire of Shadows (location):
• Surrounded by an unnatural fog
• Has a bell that chimes at midnight with no visible ringer
• Rumored to have a buried vault beneath it
• Captain Ryn Galdir (NPC):
• Smokes a pipe filled with a strange, glowing herb
• Wears a rusted, ceremonial sword from an old war
• Speaks in riddles unless bribed with rare tea

This simple trick makes on-the-spot improvisation feel natural and consistent.

5. Yes, And…

A core tenet of improv theater, Yes, And... is invaluable in D&D. The idea is that instead of shutting down player ideas, you accept them and build on them. If a player suggests something unexpected, roll with it and add an extra layer:

• Player: “I want to bribe the guard with a rare coin I found earlier.”
• DM: “Yes, and the guard recognizes it—he’s seen a similar coin once before, linked to an underground smuggling ring.”

This approach keeps the game dynamic and engaging while giving players a sense of control over the world.

Structuring an Improvised Session

Even if you have no prep, you can create a loose structure as the session unfolds. Here’s a simple formula:

1. Start with a Hook

• A mysterious stranger collapses at their feet with a cryptic message.
• An old friend calls in a favor.
• Something is stolen from them overnight.

1. Introduce a Conflict

• A noble is assassinated, and they’re suspects.
• A village is cursed, and they have only hours to fix it.
• A rival adventuring party is after the same treasure.

1. Provide Choices

• Let players investigate different locations or follow different leads.
• Offer moral dilemmas (e.g., saving one group at the expense of another).
• Introduce time-sensitive decisions.

1. Escalate the Stakes

• The villain gets what they want and grows more powerful.
• An unexpected betrayal changes everything.
• The environment itself becomes a threat (floods, earthquakes, collapsing ruins).

1. Climax and Resolution

• A final confrontation or revelation.
• A twist that changes what they thought they knew.
• A decision that alters the world around them.

By using this loose five-step structure, you can guide an entire session organically without rigid planning.

Fallback Techniques for When You’re Stuck

Even the best improv DMs hit roadblocks. Here are some quick ways to keep the session moving if you find yourself unsure:

• Roll Random Tables: Use random encounter or NPC generators to give you instant inspiration.
• Throw in a Chase Scene: If things slow down, introduce urgency with a pursuit or timed challenge.
• Introduce a Mysterious Letter or Prophecy: When in doubt, a vague clue will intrigue your players and buy you time.
• Have an NPC Ask for Help: A simple “I need you to do something for me” can lead to all sorts of new storylines.

Conclusion: Trust Yourself

Running an unprepared session might seem daunting, but with the right mindset and a few reliable techniques, you can craft an amazing game with nothing but quick thinking and player collaboration. The key is to stay flexible, use your players as a resource, and trust that you know more than you think you do.

Improvisation is a skill that improves over time. The more you practice, the more comfortable you’ll become with spinning an engaging narrative on the fly. So the next time you find yourself with no prep time, take a deep breath, roll a d20, and embrace the chaos.

Until next time, Dear Readers...