Of the many ways to give the big villains in your campaign depth and make them fun for the PCs to go up against, one of my favorites is having a developed set of motivations and other cues for the villain. If you know what the villain wants, what they’re like, and how they approach the world, you can switch into “PC mode” when you’re planning or when your players surprise you.
In other words, you can play your most important villains just like your players play their PCs: Develop a complete character, and then just react. You don’t have to know every detail of the villain’s plan, you just have to have a basis for deciding what he might do in any given situation. (Which, incidentally, is a major reason the NPCs in Masks: 1,000 Memorable NPCs for Any Roleplaying Game  are written the way they are!)
But what if that’s not your cup of tea? What if that doesn’t give you enough to go on, or you’re good at improvisation but not necessarily wired for that particular kind of improvisation?
If that sounds like you, I have an idea to share: the villain’s adventure. I haven’t tried this, but conceptually I like it — and I’m curious what you think of the idea.
The villain’s adventure
At its core, the villain’s adventure is a pretty simple idea:
- Write an adventure for the PCs
- …And then write the same adventure for the main villain
For #1, just prep however you normally prep, whether that’s a scene-by-scene outline, a network diagram of possible encounters, or writing a traditional linear adventure. You don’t have to anything differently than you usually do.
For #2, shift your perspective. Pretend that the villain is the only PC in a solo campaign, and write the same adventure from her point of view.
That could take a lot of different shapes, depending on the nature of the PCs’ adventure. For example:
- If the adventure presents a problem for the PCs to solve, then the villain’s adventure should open with causing that problem.
- If the PCs will be assaulting the villain’s lair, then the villain’s adventure is mainly about how to repel their assault.
- If the PCs are opposing a villain who is currently behind the scenes, then the villain’s adventure runs in parallel to theirs, with him using henchmen and laying traps for the party.
- If the adventure is a dungeon crawl, then the villain’s adventure is all about how she can use the dungeon’s defenses to repel the invaders.
You’re not actually going to run the villain’s adventure per se — you’re just going to use it as a loose script, an outline, a battle plan, and a tool for improvisation.
OK, now what?
Now you have two adventures: one for the PCs, prepped as normal and to be run as normal, and one for the villain, which should be a sort of “dark mirror” of the PCs’ adventure.
If the PCs change course and veer into unplanned territory, you’ll still know what the villain is up to because you have a whole outline just for him. If the PCs take a long time resolving a timed encounter, you know what that time means to the villain — she’ll get further through her adventure, likely making things harder for the PCs.
But most importantly, if you need a credible, believable, enjoyable reason for the villain to do or not do something, you don’t have to come up with it on the fly — you’ve probably come up with it already. The villain’s adventure can’t address every possible scenario, but since it was prepared in concert with (but after) the PCs’ adventure, it should cover a lot of ground.
Putting it into practice
If I give this a shot, I’ll look for an adventure with a timeline of some sort, and reverse the timeline for the villain’s adventure. When the PCs are working on “A,” the villain will be starting with “Z” — where they meet will depend on what the PCs do, how long it takes, and how thoroughly they mess up the villain’s plan.
I might also try it over a longer timeframe, with the villain’s adventure spanning several sessions of PC adventures — a story arc, let’s say. That way I’ll know what the villain is doing in the background, and if the PCs unexpectedly interact with the villain at any point during their adventures, I’ll be prepared with a fun response.
That’s just me, though — how might you use this idea? Or is it too oddball to even consider?