If you’ve never played in a one-shot game, then you are in the minority. A one-shot is where you have a willing group of players, but only a limited amount of time in which to hold a game and so need something that will only last one session. I’ve seen one-shots that were actually two or three shots, but the idea behind this kind of event is for it to start and end in short order. Perhaps you have a group of old gaming friends that can only get together once in a while. Perhaps you’ve bought a book for a new game system and you just want to give it a run around the block. Perhaps your group happens to be free all on the same night and you want to game, but don’t want to play any of the games you currently have going. For whatever reason, a one-shot is what you do when you want to role-play, but don’t have the luxury of being able to schedule a regularly occurring game.Now it seems to me that building a good one-shot involves considerations that are not normally an issue for your standard weekly game. The time constraint makes keeping things moving along far more important than usual. In your standard, one four hour session per week game, allowing a player to waste one hour being bored sucks, but is really no big deal in the grand scheme of things. Let’s say that your game lasts a year with a couple missed sessions for 50 four hour sessions total. That’s 200 hours. One wasted hour is only 0.5% of your time. If you’re running a 6 hour one shot though and one of your players spends an hour being bored, that’s 16.7% of their total time down the drain. That’s a large difference and it will be one of the memories they take away from the game; “I was bored for a good portion of it.” So we have to keep things moving and keep them interesting. How do we do that? First of all, a one-shot is a good reason for the GM to have a game plan well in advance of the event in question. Know the story you’re going to tell and restrict your players’ C-Gen so that everyone makes a PC that will have no trouble being integrated into the plot. Normally I’m completely against having a plot when going into a game, but in a one-shot this is essential. In my standard games the entire first session is usually dedicated to letting the PCs meet each other and letting me figure out who my main characters are and where they will be wanting this story to go. In a one-shot, if you spend the whole time just getting to know people, your game will end right when things become interesting. Not good. Now when picking a setting for a one-shot don’t be too extravagant. Keep the environment something that all of your players are equally comfortable in and make sure that this average level of comfort is high. If you’re running in a published setting keep it as close to the book as possible because that will allow your players to make assumptions based on what they already know/have read. Being constantly told this and that assumption was wrong because your GM had a picture in their head that differed from the one you had access to can be very frustrating especially if time is limited. If you feel the need to make changes to a given setting, be as open as possible, as early as possible, about those changes. Know how long your game is going to last (about) and have out-of-game mile stones. Game start at 4pm. At 5pm the host NPC is murdered. At 6pm the power goes out. That sort of thing. This way you can have an external control on how quickly your PCs move through the story. In a standard game I’d say this is a bad idea because you should really let your PCs have more influence on how the story progresses. In a one-shot though there should be a solid schedule or you’ll never get through your story in the time allotted. Tangents come up, distractions happen, the pizza guy will be late and he will bring you the wrong order and yet the clock ticks on. Your game has to tick on as well. Finally, your one-shot should have a definite ending and resolution. Personally, I think that all games should have a definite ending and resolution, but such a thing is far easier to engineer in a standard game than in a one-shot. In a standard game, you can take weeks to climax and to sort out every loose end. In a one-shot, you only have one shot (lol) at it. The story has to make sense and the ending has to not only fit, but it also has to seem fair. No one likes working through a complicated puzzle only to find that their solution was neither right nor wrong but was instead irrelevant. Misdirection is good in a game, but when time is a factor, the misdirection should be dispensed with early enough that your PCs can cut through to the real culprit before the end. There is a difference in realizing you’ve been fooled just in time to attempt a change in direction and finding out that you’ve been fooled and there’s nothing you can do about it now. I know you know that already, but think about which one you’d chose to experience if you had the choice. Now give your PCs that one.