Welcome to the Deathtrap: 10 Tools for Making Memorable One-Shot Adventures

This post is inspired by Lord Matteus, who was asking about using pregens for Free RPG Day.

I used to suck at running one-shots. I used to be a campaign - or-bust player, because I play at a slower pace and focus on building a very rich sensory experience that is heavy on intrigue and complex NPCs. My style fails to translate well into one-session play. Every time I attempted a one-shot it ended up a three-shot. At least my players felt it was worth coming back to.

But when a "Brian One-shot," became a joking way of describing a miniseries, I decided that I needed help. I scoured dozens of my favorite TTRPG sources for advice and kept a journal while running tons of one-shots.

This is a mix of the good points I found online, and my own observations.

1. Time is your First Priority

Time is your enemy when running a one-shot. You have a very limited time to run a satisfying game. You need to make sure that you respect your players' time and your own. This leads to several important corollaries:

Unless you are specifically testing a new system, choose a system you know very well.
Rules-light or highly streamlined games are better choices.
Find way to reduce your prep time, spending six hours preparing for a three-hour game makes no sense.
Be clear with your players start and end times. Leave a buffer at either end for socializing and feedback.
Design encounters and characters you will not need to check rules for at the table.
Make sure your notes give you a really good "cheat sheet" that minimizes your need to check rulebooks.

2. Have Pregens, But Give Space for Rolling Up New PCs

Pregenerated PCs not only are one of the best time savers you can ask for, but their design, background, or art can set the stage for the game. Your pregens are a great way to pack a lot of world building in a compact space. Nations, factions, history, tone, and the tropes of the setting can all be crammed in a one-paragraph backstory.

You can build a character with equipment or abilities tailored to the adventure, hiding clever solutions to problems in plain sight on a character sheet (so long as it isn't the only solution.) Used well pregens can make a one-shot.

If you are stress-testing a game, you pregens will let you decide which subsystems, skills, etc. are most likely to use. If you are showing off a game you love, you can display the game's greatest strengths.

Unfortunately, they are a double - edged sword. I have players that so detest pregens that they will give a hard pass on any game where they must play one. I have found that if I want these players at the table, I need to offer them the choice to build.

I have found the best compromise is to put a buffer in front of the game's official start time when I will be available for "rolling your own" if you must. But, when that time is up, pregens are what you get.

When letting players roll their own, work to streamline the character generation rules for the sake of sanity:

Restrict characters to core rules only, or a maximum of one Sourcebook per character if you are feeling particularly generous.
Use a rolling or priority system over point-buy if it is available.
If you do random rolling, use a system that doesn't require a lot of re-rolls or point-trading.
If the game requires that you buy individual items, have a set of pre-purchased kits of gear to save time.

3. Keep the Stakes High

This is a piece of advice with two facets.

The first half is common advice that you will receive almost anywhere you look for tips on running one-shots: that is to remember that the player characters here are not sacred expressions of the players' selves. They're not characters the players have worked a long time to build up. They are one-shot characters.

A good role player can still give them a lot of light and energy, but they are still not nearly as special as a long-term campaign character will be. Because of that, you are way more free to kill off characters, dismember them, mutate them, or render them permanently insane. This is the situation where your players can truly appreciate how fun it is to die in game. Especially if you have a few spare pre-gens you can toss at them too let them get right back in on the action.

The second piece of advice is when I have seen in only a few places, and best heard expressed by Harley Stroh during an interview on Spellburn. And that is to make the stakes of success or failure in the adventure high. If the stakes are not the end of the world, they should feel darned close. Rescuing a whole village from extermination, preventing the rise of an ancient demon lord, preventing a entire planet from being enslaved by space pirates, or bringing to justice the most evil man in the wild West before he boards a train and gets out of the United states.

As Harley Stroh put it, there's absolutely no reason why even first level characters, or even zero level characters it was nothing left to lose shouldn't be able to do the same cool stuff as a 16th level Wizard in Dungeons & Dragons. Why shouldn't the stakes be unbelievably high? In the end, if the players complete the scenario, they will feel as if they genuinely accomplished something amazing.

It's probably no wonder that the most enjoyable one shot I ever ran was Sailors on the Starless Sea.

4. Start In Media Res

This is one of the first pieces of advice you'll run into anywhere you look for tips on running a better one shot. And I will attest that it was one of my great downfalls when running one-shots, myself. And that is to open with action. Opening with a briefing, a lot of background, or hey chance meeting are good ways of slowing down your pace. Open with action, as it will create urgency in your players, and make sure that they're starting the game excited. You can always explain more in a flashback, or series of flashbacks scattered through the adventure.

If you start at a one-shot with a conversation with an NPC, I guarantee it will eat almost all of your time, unless that NPC dies halfway through the conversation. Players will try and pump the character for as much information as they could possibly get. Even if it means stretching the first encounter out to take half of the time allotted.

One shot don't require the same amount of player agency. You can assume that they took the job oh, and that their characters are of a temperament where they accept the mission parameters. You don't have to dangle a hook and see if they're willing to take the bait. This is one place where pre-generated characters that are engineered suit the Adventure can be extremely helpful.

5. Know What can be Dropped

Whether you're using a module or writing your own adventure, one thing that is a great piece of advice that I think I first heard from Guy Sclanders on How to be a Great GM is to know what you can afford to hack out of an adventure. Was planning a one shot, but is in your notes is the absolute best case scenario for what gets done.

Because you are up against time, you need to prioritize getting to the big payoff finale over hitting all of the encounters in the middle of the adventure. If you find things are running slow, the best thing you can do is know which part of the adventure to cut out. I like to look at the encounters at the middle of the adventure, and note which ones have high, middle, and low priority for the scenario. I find that if the players are going slow, the best thing to do is to chop out the low priority encounters.

Example

Cover to Dungeon Crawl Classics #67:
Sailors on the Starless Sea
Art by Doug Kovacs
©2012 Goodman Games

Let's break down Sailors on the Starless Sea as an example.

The adventure includes an initial encounter with a Vine horrors, then an ambush at the gates of the keep by beastmen, or a magically trapped tomb if you climb over the walls the other way. Then there is a shrine with a tar ooze that can boil characters alive in a side building, and a massive brawl with a large force of beastmen to finish off the first floor.

The second floor includes a couple of traps, including one watery pit trap beneath an enchanted pool, and a bladed trap in a strongbox.

The third floor involves a puzzle to allow player characters to make a bargain with a kraken in the underground sea. If they fail to appease it, they face a terrifying encounter that may wipe them out. Finally there's a battle against the beastmen and their shaman as they a resurrect a Champion of Chaos with human sacrifices.

If the players have played their cards right at the pool encounter, they will be carrying the flaming skulls of lawful heroes murdered by the Chaos Champion, which can be thrown like grenades to give them a better chance against the beastmen and the Champion.

Fighting the beastmen to the free captives on the first floor is the turning point of the adventure: It's the point where the player have identified their best characters, replenish their ranks, and commit to being heroic. And where they understand the stakes.

The skull pool arms them in a way that is signature to the adventure, and gives them a fighting chance. The Kraken in is there a chance to deal with a far more powerful foe by way of deception or puzzle solving, and truly makes the whole adventure seem epic.

The beastmen on the ziggurat and the Chaos Lord they raise are the whole point of the adventure.

These all are important and could be kept. But, the Kraken could be tossed if need be. It is less important to the core concept of the adventure.

The vine horrors and the beast Man ambush at the gate are cool, but they are not essential. The tar ooze, the blade trap and the enchanted tomb are all not only unimportant, and all of them can be completely removed from the map, Room and all.

If I had only 3 hours to run 'Sailors, those last 3 encounters would be skipped, and I would consider cutting the ambush once I got a sense of the flow of the room. If truly hurting for time, I might ditch the Kraken if we were hurting for time.

6. Identify your Lynchpin

In my analysis of Sailors on the Starless Sea, I noticed that some encounters are vital to get the payoff of the finale and others are not. If you look at the adventure and summarize its core concept, it is pretty easy to tell which encounters are critical and which ones are not.

Sailors on the Starless Sea is and adventure in which a mob of angry and desperate villagers besiege a ruined keep to free their kin and neighbors from the beastmen that have been kidnapping the locals. During the confrontation, they discover that the beast men are collecting human sacrifices to resurrect a Champion of Chaos, and they must go deep into the dungeon of the keep to save the sacrifices and prevent the Champion from rising again.

Confronting the beastmen to save the villagers, discovering the plan to sacrifice others, then the confrontation against the shaman, then exorcising the Champion are the three fundamental encounters without which the adventure just wouldn't work.

If you summarize 'Sailors in this manner, you could very easily re-write the entire module as needed and still hit its most important notes. You can rewrite the module to fit any time frame or structure once you know what the handful of encounters that form the core experience really are. It helps identify what can be cut and what is best accentuated.

7. The Five-Room Dungeon is a Good Start

The five-room dungeon can feel very same if it is adhered to slavishly, but for a one shot, it is one of the best starting frameworks you can work with. It can give you something for everyone. A challenge that sets the tone of the adventure, a puzzle or a trap, interactions with an interesting NPC, one or two good solid fights, and a big payoff. I highly recommend starting there when planning your one shot.

Another great tool can be the 121 Method from Guy Sclanders of How to be a Great DM.

Most one-page dungeons are also designed with a one-shot adventure in mind. They can easily be mined for great adventures that can be done in a foew hours.

8. Use Timers

The use of timers is one of the best pieces of device you will see developed an Index Card RPG Core, or on its creator, Hankerin Ferinale's, YouTube channel. Time constraints are one of the easiest ways to build attention both for an adventure overall, and for individual and counters. Having a timer that the player characters can watch slowly deplete, even if it's only represented by a die left on the table can make a huge difference to how they play and how long encounters last.

When time is of the essence, adding a time constraint to every encounter we'll keep the game moving as quickly as you need it to.

If putting a timer in front of the players telling them how long they have until something bad happens doesn't quite suit yourself, depletion dice for, say, the durability of the bridge they're on can have a similar effect.

Or, you can speed up encounters using a system like Venger Satanis' new Crimson Escalation, where critical hits or damage increase every round, giving player characters every incentive to avoid getting hit, and to end combat as swiftly and smartly as they can.

Without having a deep investment in The Campaign World, Player Characters don't have much of a sense of tension except through a timer. After all, there's no one there care about that their player character could stand to lose.

9. Use Hazards

One of the iconic modules of the Third Edition era was Eyes of the Lich Queen, and what defines that module, aside from being the one that defined how Eberron and was going to be played, was that there were no simple encounters. Every encounter in that module used its terrain, its environment, or it's situation to make things way more complicated than a single fight. The first dungeon included battles on bridges over lava, brawls with little atomata rooms full of spinning blades, and Pikes in a vaulted chamber with a young black dragon that had incredible freedom of movement. In one of its most noteworthy encounters, the player characters could even the odds in a battle by cutting the bonds on an imprisoned silver dragon, who would join the battle on the player characters side. No battle is a simple brawl in a rectangular Stone room.

Because you are only designing four or five encounters, making sure each one happens in a unusual and exciting environment can make a big difference to how fun, memorable, and fast-paced of the adventure can be. I highly recommend having a look at this video by Professor Dungeon Master where he describes a tower encounter that makes Incredible use of Hazards and timers together to create a situation where the players have to act fast, and act smart.

10. Make it Hard

Just as the last video said, balanced encounters suck. Players don't necessarily appreciate an encounter well-balanced to their character. It provides them less challenge. Likewise, an encounter with an obvious solution provided is not as satisfying as one where the player characters have to come up with their own way around it.

Providing the characters with a few assets, and an environment they can think of ways to take advantage of, then letting them come up with creative ways to use their assets is often far more satisfying.

Besides, these are one shot characters. The players don't care if the character comes out of the adventure with all of their limbs. They aren't attached to the magic items. They are willing to take bigger risks. And they know they have to make it through just five or six encounters. They will play much harder and a much riskier game than they usually would. Bring a balanced encounter at a one shot character is almost guaranteed to come up with something that they will bulldoze.

Make every encounter somewhat harder than you might have made an encounter in your campaign, and make at least one obstacle where the players are going to have to be creative and collaborative.