DM Tips for Running One-Shot Adventures

A one-shot is an adventure that starts and ends in one session. We use one-shot adventures when some players are free, but we can’t do a session our long-running campaign. I’ve run some one-shot adventures and played in several, and they’re a great way for people to try out character concepts!

Here, I’ll talk about the set-up and prep for a one-shot, as well as tips to keep in mind while actually running a one-shot.

Set-up

While I keep a lot of notes online, writing ideas in a notebook can help you brainstorm ideas.

For us, a one-shot means new characters! The DM communicates out what level the characters need to be and any additional equipment they might have. For example, characters starting at 10^th level probably have more gold than a character at 1^st. I also recommend giving the players some information about the adventure they will be playing. This helps set expectations, and players can create characters with this information in mind.

It is paramount that the players have their characters ready prior to the start of the session. This saves everyone time—time for players to ask the DM any questions they may have, and time for the DM to understand what sort of party is going to participate in this adventure. Of course, this means that the DM has to tell everyone character creation details well ahead of time, so everyone can come prepared!

DM Prep

I find that the more time I have ahead of the one-shot to prep, the better. The somewhat spontaneous nature of our one-shots usually mean I have somewhere around a couple days to prep.

You probably want to identify the level at which people should create their characters. I usually either commit to a level (for example, a 5th-level adventure) or a one-shot concept first (then decide a level right after). But those are the core pieces of information to start shaping your adventure.

The initial concept can be vague—something like “an adventure through a magic research facility run by a rogue AI” or “an adventure with a cambion pirate captain” or even “an adventure that uses an allip” (or even vaguer. I like to have an idea of the major antagonist or the setting of the adventure, at least.)

Either way, you should communicate at what level to create characters as soon as possible.

After you know what level they’ll be, you can decide if they have any additional gold or equipment. I usually use the “Starting at Higher Level” table near the end of Chapter 1 of the DMG as a guide. Using the amount of additional gold, players can purchase any equipment they might want.

Some players might want to purchase magic items, so decide whether or not you want to allow that. You can even curate a list of available magic items for characters to choose from– I highly recommend this if characters are allowed to get magic items.

You should also decide which sources you want to allow character options to come from. Do you want to open up Unearthed Arcana or certain homebrew sources? Do you want to keep it to only official sources, or to just options from the Player’s Handbook? Regardless of your choice, be sure to communicate it to your players as soon as you can, preferably alongside level and equipment communications.

Once you’ve set those guides down, it’s time to actually prep the adventure.

I struggled to keep one-shots within our 3-4 hour time slot until I figured out the best way for me to outline the flow of action. In players groups of two or three, I can usually fit 3-4 scenes into my outline. Any more than that, and it’s best to keep it to 2-3.

What do I mean by scenes? A scene is much like the rules’ description of an encounter. It can be combat, social, or exploration-based. I usually pick two of those three to focus the adventure. Let’s take the three ideas I mentioned before—I’ve fleshed them out into adventures and run them.

An adventure that uses an allip was an exploration/combat concept. While there were certainly social aspects to it—the players picked up an NPC along the way that they had to deal with—my prep focused around the exploration and combat.

It’s also super important to know what you can and can’t improv. I know that room dimensions and descriptions are hard for me to come up with, so I’ll prioritize writing down those descriptions in my prep. On the flip side, I’m more confident in filling in NPC details on the fly, so if I’m okay if I don’t drill down on the details during prep time.

My initial, rough outline for this adventure was:

• Scene 1: the adventurers find the sunken stone tower. They have to figure out how to climb the tower to enter, as the entrance is now below ground level.
• Scene 2: the adventurers find the allip’s clockwork constructs who are protecting the library. The constructs attack as soon as they sense the adventurer’s presence.
• Scene 3: while the adventurers examine the library, they find its former occupant’s study. The allip appears and lashes out at them.
• Scene 4: the tower begins to crumble!

It’s a sketch, there’s not a lot connecting the points. Detail needs to be added here, but at least I know the points I need to hit—which stops along the way are important for the journey.

An adventure with a cambion pirate captain began as a combat/social concept. Thus, I determined which monsters I would be using, and I familiarized myself with their stat blocks. Its outline looked like this:

• Scene 1: the adventurers find themselves tied up at the bottom of a ship—how will they proceed?
• Scene 2: the adventurers must contend with some of the ship’s crewmembers as they make their way up to the deck.
• Scene 3: not only is there a cambion captaining the ship, there’s also an air elemental providing wind for the sails, as well as a number of crew combatants. How will the adventurers deal with these threats, and how will they get the ship back to port?

One-shot prep, feat. handwriting

Combat can take a lot of time, so consider using one big combat encounter over multiple. If your adventure potentially has more than two combat encounters in them, make sure that the party can either resolve the scenes quickly in-combat or that there’s a way to resolve them without fighting.

An adventure through a magic research facility run by a rogue AI-like construct had a social/exploration focus. The “rogue AI” was a magic construct named Proxy that had control of the entire facility, so the PCs could speak with them at any time a la Siri or Alexa. Its outline:

• Scene 1: the adventurers find the magic item display room, and they “see” a memory from just before the accident. The memory shows some of the missing people.
• Scene 2: the adventurers discover that Proxy is moving the rooms around. They find a research room with an unfinished letter by one of the researchers in it
• Scene 3: the adventurers investigate what’s left of some of the construct experiments, and it’s obvious that something is wrong with Proxy
• Scene 4: the adventurers must figure out where the missing people are while negotiating with Proxy.

There are a lot of details that get added in. But, regardless of how much prep you put in, don’t be afraid to let the PCs take the wheel. This one-shot was the best to run because of how the players took the information I gave them and put their heads together to solve the problems the adventure presented their characters.

Lengthy exploration sequences where the adventurers are wandering from room to room can take up a lot of time. You can move things along by reminding the party of their objective and by cutting back on elements that don’t move the party forward. The DM is the narrator, and that means that you have the power to direct the characters’ focus.

You can also introduce a time element—in-game time restrictions can do a lot to move things forward! One particular one-shot stands out in my memory because the DM literally set a timer. The pressure of an IRL ticking clock definitely kept us moving forward in-game.

The same goes for social scenes. It’s helpful for the characters to know exactly what they’re looking for—the more specific, the better. Establishing a concrete objective in a social encounter can prevent wandering conversations and lost time.

As with all DMing, it’s vital to know your particular group and what’s fun for them. You know how much time you have for the session, and you know the people you’re prepping for. These tips are meant to help you prep a structured and short adventure that moves quickly. But if your players want to spend more time in a certain place, let them!

Running the Adventure

Now it’s time to run the adventure! Make sure you have stuff like stat blocks or rules references already pulled up to cut down on the time it takes to reference them.

While you’re running a one-shot, remember to:

• Direct the pace of the game while being away of the time available for the session
• Slow down where the characters show interest
• Speed up where the party stops moving forward
• Be intentional with your narration and where you’re pointing the characters’ focus
• Let the PCs come up with creative solutions

And of course, don’t forget to breathe and enjoy the game!

All of my one-shots take place in one world, though they occur in different times and places. Even if these characters won’t be played again, let them have an effect on the world! It’s fun for the players to recognize NPCs or organizations that they’ve come across in the past as different characters. It provides a sense of cohesion in the world, and it lets the players know that their adventures have an impact—even if it’s a one-shot, their choices matter.

It took us a while to find the right pacing. I hope this helps, especially for DMs who started off running a long campaign and want to give a one-shot a try!