There are many reasons that as a DM you might find yourself running a one-shot. Whether you’re trying to entice new players with their first adventure or you need to come up with an alternative because half of your regular players couldn’t make it to your scheduled session, almost every DM has had to use a one-shot adventure. But how is a one-shot different from running your normal campaign?
One-shots are typically run when you either a) are trying to fill the time of a normal gaming session or b) aren’t sure that you should put all the effort into creating a vast world. The essence of a one-shot is that it is a self-contained adventure that only lasts one gaming session.
So first, try to understand what your time constraints are. Will your game be 3 hours? 6? 8? Different amounts of game time allow for different types of play. For example, sometimes puzzles or combat can really slow down the progress of a game. Will you have the time for that?
If you know your group well, you should have a basic idea of how long it takes them to complete certain tasks. Plenty of groups spend a lot of time developing what they consider “fool-proof” plans. In order to speed them along, introduce timed events so that they feel that they always need to be moving along. Using hourglasses or timers will help make sure that the time constraints in the game world translate to the real world.
Simplify Your Setting
Next, start with a very simple plot hook. There won’t be a lot of time for character development or for players to see changes in NPCs over time. There also won’t be any time for players to backtrack across a world map. Simplify your game state as much as possible. Generally in a longer campaign, you can add a whole bunch of plot hooks any time and anywhere you want. But for a one-shot, try to keep the focus on one hook. Now, that doesn’t mean that you need to railroad your players into completing the hook in a certain way. Make multiple win conditions available. For example, in The Lord of the Rings, the party first tried to get through the Misty Mountains through the Redhorn Pass, and then through the Mines of Moria. Make separate but equally difficult avenues of success available for your players.
Then you can add NPCs that are available to assist your party. Perhaps those NPCs need to be paid in order to be used, or they have a condition that your party must accept during the one-shot. For example, if you’re running a heist one-shot, perhaps the NPC wants the party to steal an additional item for them. However your party manages to acquire help, use the NPC as a brief assistant, not as a glory stealer. The NPC might know a secret password that will allow your PCs to take a shortcut. The NPC should not be the only character who can complete a certain task.
Also, don’t be afraid to kill your party members. It’s a one-shot, so players shouldn’t be that attached to their characters. However, unless your players came prepared with multiple character sheets, try not to kill them in the first few hours of play. Otherwise you’ll have someone sitting at your table with nothing to do but be a distraction to the other players
Putting it all Together
A one-shot adventure should have enough content to cover a single gaming session. Try not to go overboard when planning out a one-shot session. Use NPCs and real life timers to help move your players along. If you need help with creating encounters in general, check out our posts about 30 Minute Dungeons and Creating Encounters. Happy DMing!