As the foreword to the original “white box” edition of Dungeons & Dragons said of the brand-new medium of fantasy roleplaying games: “While it is possible to play a single game, unrelated to any other game events past or future, it is the campaign for which these rules are designed.” There’s no question that this concept of the campaign as a longform shared-narrative story is still the foundation and best part of the experience of playing a fantasy RPG. But at the same time, every campaign effectively starts out as a single adventure, and there’s something special about that experience that makes one-shot games great fun.
Why One-Shot ?
Even if your process of running games is focused entirely on a long-term campaign, opportunities and reasons to run one-shots are always present. At the top of the list for many groups, playing a one-shot is a great alternative to cancelling game night if most players can make it but enough are absent to make running the regular campaign game a nonstarter. Or in a campaign that features a significant break point between different parts of the story, including an extended downtime between the previous story arc and the next, taking a week or two off to run one-shots can help heighten that break.
Just as common is the opportunity to run a game for new players — friends, classmates, coworkers, and so forth — who have never played an RPG before but are keen to try it out. But whatever inspires your urge to run a one-shot adventure, the following things are worth keeping in mind.
Pregens For All!
A one-shot game by definition should be started and finished in a single session. This means focusing on the adventure first and foremost, and nothing gets in the way of that better than dedicating a big chunk of the session to character creation. Even with really straightforward games, brand-new players wanting their first taste of a fantasy RPG most likely have zero interest in the niceties of the character creation process. So ignore that process with a handy selection of pregenerated player characters.
Some one-shot adventures might come with their own set of pregens, built specifically with the adventure’s story in mind. But if not — or if you prefer to homebrew your one-shot — the Internet is full of pregens for literally every RPG system out there. (If you’re playing D&D 5e and are looking for 1st-level pregen characters, feel free to check out the free, new-and-young-player-friendly heroes I created for the Hidden Halls of Hazakor starter adventure.)
Going Low
Especially when running a game for brand-new players, one-shots are often best when focused on straightforward starting characters. Even for players with plenty of experience in higher-tier campaigns, taking a break to go back to being a neophyte can be fun, and makes it more likely that players can focus on the fun of the single-session story as opposed to looking up rules for a higher-tier character whose features they’re not familiar with.
One option for a regular group who dip into one-shots to break up a long-term campaign is to treat their one-shot characters as side characters, letting them gain experience, new levels, or new features between one-shot games. Advancing characters by design this way is a good way to create higher-powered characters ready to play future one-shots, even as the lower-powered versions of the characters can be archived to be reused as needed.
Keep It Simple
Especially if you’re a GM who loves having your adventure scenarios challenged by highly focused, optimized characters, take a step back from that when running one-shot adventures. Complex and optimized characters are great fun in a campaign where players are building those characters over time. But it can be a huge challenge to process and master a complex character in the short time that a one-shot allows.
For your one-shots, encourage the use of simple pregens or straightforward character builds that be assembled in just a few minutes at the start of a session. Keep in mind the general rule that spellcasters are often more challenging for new players than combat-focused builds, and don’t be afraid to customize the one-shot to allow an unconventional party built around ease of play. If a group of brand-new players all want to run martial classes or warrior builds, run with that, directing your complexity-loving GM’s brain to reshape the adventure and let an unconventional party shine.
Standalone Adventures
One-shot adventures are in tremendous supply across the hobby, so even if you’re looking for a one-shot on short notice, you should have little trouble seeking out and finding one that feels like a good fit for your group. Among many other options, adventures created for organized play and convention games are often focused on a single three-to-four-hour session’s worth of gaming, and provide enough background information to let you run your game as a standalone even if the adventure is part of a larger series.
If you find yourself running a lot of single-session adventures, you can also keep an eye out for anthologies of one-shots or standalone adventures. (I am obliged to point you in the direction of Fantastic Lairs, a book created by Mike Shea, James Introcaso, and myself that provides a wide range of scenarios that can be run as one-shots or integrated into a larger campaign.) Or if you prefer to homebrew, I wrote up a short guide to designing a single-session site-based adventure in about 10 minutes that’s worth looking at.
Flexible Foes
Especially when running a one-shot for low-powered or beginning player characters, be ready to adjust the math of monsters and other challenges on the fly to keep the adventure fun. When a group of brand-new players ready for their first exposure to RPGs sits down for your one-shot adventure, having their characters fail badly or die outright makes for a bad introduction to the hobby. In a longer campaign, ups and downs are an essential part of the heroic narrative, with each failure the characters face making the victory that follows feel sweeter. But a one-shot should be focused almost entirely on wins for the heroes, making sure that setbacks are minor and easily overcome.