So the idea of a one-shot is simple: You have a group, a challenge they must face, a fancy setting around that, and a resolution at the end. But what do you actually do for that one-shot? And actually, what makes a one-shot a good one-shot? I'm writing down some tips here, with my own Headhunters
one-shot as the occasional example.
A measurable goal
Even if the players may not know what it is at first, there is a specific goal to reach or fail at reaching. This can be anything, really: Save the princess. Find out what's haunting the woods. Steal the shiny object. Dig deep into the dungeon and
awaken an ancient evil
find the hidden treasure.
The important bit here is that the goal must be measurable. A one-shot must be brief, 3 to 6 hours, not an indefinite amount of time. No 'explore and just see how far we get'. If your party's task is to improve the kingdom, and there's always more things to do, then there's never an actual end to the story.
Choices & Consequences
A one-shot, like any other rpg campaign, is a dynamic story. The players are actual actors that should have agency and impact. If their only role is to roll, they're not characters, they're just readers. There should be alternative approaches, or a choice in side.
Let's look at Headhunters
for a second: Its first half requires the party to kidnap someone. They can be creative on how to snatch him, and a hundred parties would likely end up with at least twenty different methods. The second half involves three different ways to overcome the twist. Speaking of:
The Twist / The Complication
An adventure is often not straightforward. The party doesn't just march straight into the throne room to overthrow a tyrant, or just grab an abandoned object. They are trying to reach a goal, but are surprised with a twist (which gives them a new goal) or a complication in the way of achieving their original goal.
This challenges the players to think of ways to overcome their situation, and engages them in an actual story. 'There was a vampire, we killed him' is simple. 'The local lord was making people disappear, we went to talk with him and he turned out to be a vampire!' is something that sticks with people.
To Stat Or Not To Stat
If you're playing a D&D-like module, often it says 'for characters level 7-9' and includes specific enemy statblocks. Upside here is that the GM knows exactly what they're dealing with. But it does restrict you to a specific level and system. Not that that's bad, but some writers may find it hard to balance opposition.
So leave it up to the GM! For example Headhunters
states sample SR6
enemies to use, but doesn't mandate those. A GM can adjust opposition to fit their players, or even use an entirely different system. It's fine to stat everything out, but also fine to simply use intended difficulty indicators.
Always stays the same
Imagine a dungeon crawl. You fight monsters. Move. Fight monsters. Repeat. Boring, eh? This is why there should be a variation of challenge types. Maybe you need to investigate how to break in first. Or convince the Watch Commander to stay out of your way. But there needs to be variation in your scenes.
The general rule of thumb is that after a scene, the next scene should be different. In Shadowrun for example you have so-called 'Legwork' scenes: You prep before you sneak in / face an army of undead. The dungeon might have you navigate some traps, or a puzzle. And a ball might suddenly involve a duel.
A one-shot is limited in length, generally at a timeframe of 3 to 6 hours. So it's important to tune the length into a manageable section. No 'four different fights and two complicated puzzles' if you want your players to finish the plot today. Or figuring out a political intrige and still have time for a dance-fight.
In most RPG systems, combat takes a long time. But a scene where the players have to do an awful lot of investigating without clear end, also takes a long time. Be careful with intensive scenes, don't use too many. The same goes for twists/complications: For a limited timeframe, a single one suffices.
Infinite Featureless Planes
Speaking of fights: In some systems, you really need a battlemap. With others, Theater of the Mind (aka: imagination) and some scribbles may suffice. But no matter the situation, the last thing you want is a boring fight that takes place in a large room with a lengthy duel at ten paces.
So give the GM some tactical ropes. Have some rocks on the battlefield, or describe that there's car-wrecks laying around that serve well as cover. Put in complications to make it harder on the players, or tactical advantages that will turn the tide in their favour. Make it memorable.
Imagine a crucial scene that only a Cleric's Divination spell can solve. Or an endless list of 'if A then B, if C then D' specifics. In both cases, the one-shot is too specific. The first situation assumes a specific party-composition, which only works if you also make the party. The second is overly descriptive.
Here's something you need to know: The GM has agency! Which means you need to give them enough slack to deal with situations you did not expect. Headhunters
goes to the extreme here: It states multiple possible approaches for the GM to steer players towards, but that's literally all I wrote!
There's countless different one-shot styles, countless different stories to be told, and countless groups to
enjoy these! So don't go 'X has Y, I don't, so I suck'. Headhunters
lacks battlemaps, statblocks, and lengthy narrative bits. Is that bad? No. Is it mandatory to do it exactly like that? Nope. Make your own adventure, get help from the awesome community, and enjoy April!