Often, the plot of a one-shot is simple. Go into the forest and confront the bandits. Clear the demons out of the old temple. Find and destroy the Imperial signal base. As I’ve frequently written on here, a good rule of thumb for a one-shot is to start with a simple, straightforward plot and then twist it. Interfering Factions is one such twist that adds player agency, roleplaying opportunity, and time flexibility to your one-shot; in this sense, it will almost certainly improve it.

How do you do it?

Take your simple one-shot and add another faction. This faction’s motives need not be complex, but they do need to be orthogonal to both the players and the antagonists. You need to imagine a way in which they serve as allies, and a way in which they could serve as enemies – and let them move between these extremes.

It’s usually a good idea to drop hints as to their existence at the outset, or at least make their appearance be easily predictable, so they make sense in the one-shot; you can easily present them as a possible antagonist or friend, but be careful to not commit too hard to either,

Why does this help? Well, it gives the players genuine choice as to how they approach them – they are potential allies, if they can be persuaded or bribed, but they could also interfere. They give a stakes-attached scene which isn’t necessarily a fight (at least at first).

They also, crucially, help with timing if you are running a game at an organised convention or similar. Their introduction and interaction can be flexible – they can appear at a key point to rescue or help the PCs, or betray them at the end – they give flexibility to the GM as well as the players.

Examples

In my 13th Age Glorantha adventure The Beard of Lhankor Mhy, the PCs encounter a lost, injured squad of the hated Lunars as they near the big bad – can they put differences aside to rescue their friends? In the adventure as written, the Lunars have a good reason to want an alliance, but I have sometimes seen the PCs and them turn on one another after the main plot is concluded.

Or, to take one of the most obvious fantasy ur-plots,

Goblins are raiding the caravans on the forest road!

The basic adventure is to track them to their cave lair and defeat them via dungeon crawl. But add in a interfering faction – here are a few ideas

• A rival goblin clan who the goblin chief betrayed to set out on his own
• The feckless human guard who insist on solving the problem themselves
• An arrogant noble merchant prince who seeks to monopolize safety along the road

Or, for a science fiction example,

Someone on Planet X has developed a bioweapon!

The basic adventure is that you find who has the one sample by skulduggery and intrigue, then raid them at their suspiciously-combat-prepared lab. But add in

• Angry eco-terrorists who want the bioweapon for their own ends
• A rival company who seek to destroy the weapon so their own can gain the patent
• A disgruntled scientist (in an armored exoskeleton) who seeks to release it in the lab for revenge

You can, of course, add more than one interfering faction, and even build an entire one-shot out of three or more rival factions (for a great example of this communicated with Robin Laws’ customary ease-of-play, see The Strangling Sea for 13th Age). Have you used interfering factions in play? Be sure to comment and let me know.