I’m going to sketch out here the procedures that allow you to keep to time and a swift pace even using a traditional dungeon design. I’ve called it the Collapsible Dungeon, and (to give credit where it’s due) adapted the idea of plot keys from the excellent Cypher System adventure anthologies Weird Discoveries (for Numenera) and Strange Revelations (for The Strange). These are probably some of the best examples of ready-to-run one-shot games out there, so they are well worth a look.

So much of old-school adventure design relies on a location-based structure, and when you play in one your pacing is often at the mercy of the players; with your home group you can probably predict how fast they’ll eat up the locations, but at a con game it’s much harder to know. I’ve run games where the players slowed to a crawl, insistent on searching every door and cautiously risk assessing every option before proceeding, and also games where the players charged through rooms keen to get to the climactic encounter ignoring all my carefully-laid reveals.

The First Location: The Entrance to The Dungeon

As the first location, everyone is going to explore this area, so make it as exciting and punchy as you can to start the session with a bang. There should be a puzzle or challenge here, or preferably both. Lay out the thematic content of the dungeon – if you’re exploring a Yuan-Ti lair, maybe the doorway is embossed with snakes, or there’s poison traps everywhere – or maybe just a huge snake across the doorway’s arch that springs to life and attacks as they approach.

The Middle Locations: The Collapsible Bit

Now prep between 5 and 10 locations (in a dungeon, these are likely to be rooms, but could also be corridors or even wandering encounters). Start the PCs with a fork in the corridor, or two mysterious doors, and allow them to encounter the rooms and encounters prepped is as logical an order as you care to make them. You do not have to cover all the locations needed to make your dungeon consistent – establish that they can fast forward through empty rooms – each of these middle locations should contain a challenge or puzzle to solve, or a secret to discover, and be linked to the overall theme.

Useful props for this section to consider in your prep are to have each location on one sheet of paper or index card, so you can select the next one quickly and put it to one side when the location has been explored. You can also do this with an (un-labelled) map, indicating the rooms the PCs progress through even as you decide on the spot what to encounter in them.

Sprinkle these middle encounters with 2-3 plot keys, adding them in according to the pace and timing of the game.

Plot Keys: The Steps to the Climax

Plot keys are the macguffins that lead to the final resolution of the adventure – they could be literal keys, or clues to the dungeon’s back story, or useful items in the final challenge. These are not tied to specific locations as prepped above, but you should decide when they are encountered. When all the keys are collected, you should be ready to push swiftly to the final encounter, and by pacing this carefully it should be easy enough to do that.

As for timing, in a 3 hour con slot I’d probably want 2 keys, one to be found on the 1hr mark and another at the 2hr mark or so – depending on the system and how long you think the final confrontation could be. Similary, for a 4 hour slot I’d probably have 3 keys spaced evenly as above.

The Final Location: Climactic Battle

This is the boss fight, the encounters that will lead to the resolution of the dungeon and completion of the adventure. This encounter should be foreshadowed with plot keys and locations in the middle section, and should be a challenging fight for the PCs even with any plot keys that will give them a boost against it. By keeping to time and doling out keys as the players progress you should be able to make it all come together in a satisfying conclusion.

Now, I’m quite prepared to admit that this ignores many of the long-standing traditions of OSR play and dungeon exploration, but I think that there’s more to gain in getting pacing right than there is by the procedural exploration of a hidden map. After all, it’s just another procedure, right? What do you think?

And keep an eye here for an example of a fully prepped one-shot OSR dungeon designed according to these principles.