1. Choose the Right System
First, only attempt to run a game without planning if you’re really familiar with the system. You’ll be flying without a net, so simultaneously trying to figure out a new system is not ideal. The more familiar you are with the rules the better, because it spares mental processing power. You’ll need all your ingenuity and energy to create the narrative, and you can’t afford to waste any trying to remember how attack rolls work.
If you have the luxury of being familiar with multiple systems, choose the one with the simplest difficulty rules. When building encounters without any preparation, intuitively knowing how hard to make things is a must. Mouse Guard is a great example. In that system, all you need to consider is how high a PC’s skill is, and then you can set a difficulty that grants the appropriate level of challenge.
Systems like Dungeons and Dragons or Anima Prime are not ideal. In D&D, you have to remember a load of equipment bonuses, class abilities, magic items, and spell effects that might affect the roll’s outcome. Even in the slimmed down Fifth Edition, there are too many factors to manage. Anima Prime, much as I love it, is even more difficult. Because any mechanical challenge in that game must be resolved through conflict, every encounter requires planning. You can’t throw down any quick and dirty obstacles because Anima Prime doesn’t have rules for them.
This is the only instance where I will acknowledge the advantage of systems like Call of Cthulhu or Dungeon World, which base difficulty on a character’s skill rather than the task being attempted. In those systems, the GM doesn’t even need to set a difficulty; it’s baked right in. That will certainly make things easier when you’re spending all your mental resources figuring out what’s supposed to happen next in the plot.
2. Forgo Extended Conflicts
Some GMs already use combat sparingly; others embrace it as the lifeblood of the game. Whatever your predisposition, you’ll want to avoid any rolling of initiative if you haven’t had time to plan. This includes non-violent conflict systems like the Burning Wheel’s Duel of Wits, as well.
To some, combat may look appealing in this scenario. After all, combat usually eats up a lot of time, which could give the GM a breather while trying to plot out the story. This is a false hope! While combat does occupy time, it also requires a significant chunk of the GM’s concentration, and that resource is spread too thin already.
If you mess up setting the difficulty for a single roll, no big deal. But combat in most systems carries much higher stakes, and you’re more likely to get it wrong. Even in an easy system like Mouse Guard, combat is much more labor-intensive than a single roll. You have to figure out the bad guys’ stats, their equipment, and their tactics. Mess up by making the enemy too weak, and your players will undoubtedly notice that they’re just waltzing through the opposition. On the other hand, accidentally making the enemy too strong will wipe out your party. In many systems, that’ll mean a lot of PC deaths, which you probably don’t want.
You can still have characters involved in exciting sword fights, but mechanically they should be resolved with a single roll. Even if you’ve never done this before, it’s super easy. First, describe the enemy’s attack. Second, ask the player to describe their defense.* Then roll and narrate which was successful. This narration should bring an end to the fight, with one of the combatants either driven off, incapacitated, or robbed of their objective. That way you avoid repetitive rolls and can move on to the next exciting thing.
3. Set a Simple Objective
So now you’re armed with a good system and are prepared to resolve conflict with a single roll, but what about the story? Any intricate plots you try to weave without planning are sure to collapse. For that matter, even simple plots may fail because you haven’t thought of any motivations or goals for the NPCs. To make life easy for you, it’s time to let the PCs take the wheel.
The best way to do this is to figure out something the PCs want in-character. In many games, this can be as simple as a chest of loot, because gold and silver are always popular. If your PCs aren’t after treasure, they’re sure to want something: food for their village, a rare artifact, a cutting edge airship design, whatever seems like it will most interest them.
Once you have the thing your PCs want, tell them where it can be found. Make sure this knowledge comes from a trusted in-game source. When the PCs know the location of their objective, you can be pretty sure they’ll go out looking for it. If they’re reluctant, you have my permission to tell the players that this is the only adventure they’ll get tonight.
After the PCs set off on their quest, you only need to react to whatever they do. Just describe a few hazards based on wherever the objective is, and let the PCs figure out how to proceed. Then call for some rolls to see if their plans are successful. That won’t always be easy, but it’s a lot better than trying to figure out complex plots in the spur of the moment.
4. Focus on PC Plot Hooks
Setting a simple objective and letting your PCs find their way to it is an effective method when you haven’t had time to plan, but it might not satisfy you. If you’re a GM who loves narratives, then a simple adventure in pursuit of treasure won’t cut it. But you still haven’t had time to plan, so what are you supposed to do?
This is when it’s especially important to look at the plot hooks the players have provided to you. In a system like Torchbearer, this will be provided for you on the character sheet in the form of beliefs and instincts. In games without features like these, you’ll need to figure out what your players are into some other way. Maybe a player previously expressed interest in a particular plot or was friendly with an important NPC; now’s a good time to bring it up.
Using a PC plot hook allows you to make the session relevant to the larger narrative and saves you a lot of work. You don’t need to plan out a complicated series of events. Rather, like with setting a simple objective, you just describe the plot hook and wait to see what the PC does. Then you react accordingly.
For example, PC Mike’s goal is to discover proof of the ancient Sea People, so you only need to let him know that his character has spotted some strange ruins where none should be and then ask what he does. If Mike goes to investigate, that’s your cue to include a few mysterious artifacts, the meaning of which you can reveal once you’ve had time to plan. If Mike goes to get help, that’s a signal to you that the ruins should be teaming with opposition. Otherwise, recruiting all those mercenaries will have been a waste of time.
When employing this trick, be sure to only approach players you know are active and engaged with the world. Player who require a lot of prodding to investigate the plot hook you put before them won’t save you any work.
5. Recycle Old Encounters
It’s all very well to set a simple objective and use PC plot hooks, but what about the opposition? How do you make sure you can come up with encounters on the fly that will challenge your players and make them feel a sense of accomplishment at the end? Simple: bring back what’s worked before. We’ve talked about reusing monsters; now it’s time to reuse an entire encounter.
If you’re stuck trying to think of something to happen, look at your notes for encounters that went over well before, and modify them for the current situation. When the encounter you’re modifying is from the same system you’re currently using, you can bring the mechanics along for the ride, but this isn’t all that important. As long as you choose the right system, substituting new difficulty levels and dice rolls will be straightforward. What you’re after is the encounter’s narrative.
For example, let’s say your PCs are a group of explorers sailing off into a haunted ocean. You know they’re looking for a sunken treasure ship, but what kind of obstacles should you put in their way? Well, you remember one time in a different game the players enjoyed fighting a hydra that would grow new heads when it was injured. So you describe monstrous growths of coral climbing over the ship’s rail and how any blows only make them grow faster!
You can do this more than once. In fact, so long as you have a decent library of encounters, either in your notes or stored in your brain pan, you can run the entire session this way. Don’t worry if you can’t remember the exact mechanics of the encounters you’re recycling. Chances are you’d have to change them anyway, and it’s far more important to have ideas for what happens in the narrative.
6. Raise the Stakes!
Most GMs like to plan each session well enough that you can ensure a satisfying ending for all. But you haven’t had time to do that. So how do you make sure your session is more than a series of competently balanced encounters? You raise the stakes.
Raising the stakes is a basic tool for storytellers, and you’ve almost certainly used it in your games before. Now you’re going to turn it up to 11. Whenever your unplanned session starts to falter, make everything bigger and more intense. Any mistakes or inconsistencies you’ve accidentally created will be forgotten in the rush of excitement.
To continue from the earlier example, your party of haunted-ocean explorers have defeated the miracle-grow coral, and they’ve decided to investigate where the coral came from. Problem: you haven’t thought that far ahead. Instead of struggling to create a half-baked explanation, you describe how a leviathan emerges from the depths, ready to devour the ship!
Normally, you want to be cautious of how often you raise the stakes, because you can only do it so many times before it feels mundane. But having no plan is a special – and hopefully rare – circumstance, so go all out. You can even raise the stakes all the way up to a cliffhanger if you need to, leaving the question of how you’ll get back down for next week after you’ve had some time to plan.
Planning is critical to the GMing process, and I don’t hold with the idea that game masters should be able to improv their entire story. That said, sometimes there just isn’t time to plan, and you need to be prepared. Keep these moments infrequent, but when they happen, go forward with confidence. So long as it looks like you know what you’re doing, then the players will go along with it and everyone will have a grand old time.
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