As a DM for One Shot Or Not, one of the most difficult aspects of the show is writing a One Shot that can be completed in 3 hours with a break in the middle! I love a good challenge and will share some of what worked for me.
Session Zero! This should be a no brainer, but One Shots need session zeros too. The modifier here is to let the party in on the shape of the game, let them know what to expect but give them room for shenanigans too. Come up with a key word or phrase to let the group know to get back on task and do the main quest. Give them some time to roleplay during session zero to get a feel for each other’s intentions and establish their own.
Breaks. Let the players know you’ve got an intermission planned so they have 10-15 minutes to catch their breath and even strategize together. When planning the story beats, give yourself a fun cliff-hanger to leave them on just as you go to break to build that dread or anticipation.
What’s DnD without shenanigans? As much fun as it is to have the party go after Red Herrings or hyper fixate on random NPCs, this isn’t a campaign! You’ve got 3 hours to tell a story and there’s not a lot of room for filler. As a DM, check the pulse of the table: is everyone invested in this scene? If not, move along! If they are all RP’ing and invested as a group, give them some time to explore that but give yourself a way out after 5-10 minutes so you don’t use up all the time you need. I love having an NPC show up to drag away the NPC (late for work, spouse is calling them home, Timmy’s stuck in the well again?) and shift the scene back to the main story line.
Puzzles. Always give yourself MORE time than expected for any puzzles you plan. When players are really into their characters, sometimes they make choices you don’t expect them to normally make. Or sometimes the dice decide nobody can effectively solve this puzzle. Plan for fun ways to give hints and move them along, but don’t outright solve a puzzle for them. If the answer you’re waiting for isn’t coming around, keep an ear to their ideas and adapt the solution to fit. Reward outside the box thinking and give everyone a chance to work on the puzzle. Also, during session zero, let the players know to expect a few puzzles so they have at least one character who has the skills required.
Timers. Yes IRL Timers! Nothing like a countdown to Doomsday to keep the team rushing towards the finish line. This is especially effective during combats nearing the end of your time limit. I’ve done this a few ways. Once, during a zombie one shot, I had the players make a CON save every 30 minutes of real time to stave off the infection. And every increment of time increased the DC of the save which made the players rush through the ship to find a cure or solution to their dire situation. Another effective use of the timer was for the Strixhaven finale. Murgaxor was completing a Ritual to steal the lifeforce of everyone on campus! We set an 80-minute timer to countdown everyone’s death and the players skillfully pushed their plans and defeated their foe just inside the time limit.
I hope you find these tips helpful for your One Shots! I’d love to hear about how you make games work on a time limit, DMs can DM me on twitter/instagram as @chefcargs