The Doom of the West Marches

Using Cortex Prime RPG to build a West Marches game

I’ve been enamored by the possibilities of using the Cortex Prime RPG for games. Supers is an easy and proven genre, I’ve done a hack of the old Justifiers RPG, a Suicide Squad-ish one-shot. Cortex is such a solid toolkit. When thinking about the next version of my West Marches game Cortex ranks high on my shortlist and the Doom Pool option is a big factor for that!

The Doom Pool is a Cortex option that can be used as a threat level, pacing, or resource mechanic. In the West Marches, there are expedition sites. These could have Doom threat level ratings to start the ‘exploration scene’: the old tower a day from town might be 2D6. That haunted wood is 2d8. I would figure out a way to encode this onto the shared map whether displaying the dice outright or some skull icons. ie; a skull = 2d6, 2 skulls 2d8. Maybe some sites on the map have a rating clearly displayed, others are unknown because no one has returned to say anything about the place!

I would start journeys at the minimal 2d6 threat rating, with possible adjustments based on region, has it been previously traversed?

Doom Pool as pacing

In the rules, the GM can end a scene by spending 2d12 from the Doom pool and decide how it ends. This one is hard - does this mean expelling the party out of the site, smash-cut to camp, or back to town even? Or is it just the current encounter that they ‘lost’ and are routed back to a “save point” or camp? What does that mean in a sandbox game? I think this feature of ending a scene is good, it feels like it creates a mechanical timer made visual by the size of the dice in the pool. I see some IRL playtesting to find answers here.

Sessions have real-world time constraints. Running out of real-world time could mean testing against the current Doom Pool to see how characters make it back to town and at what cost, easily leaning on the effect die for scale or meaning.

Having a Doom pool opens up Sfx for manipulating the pool via abilities, magic, etc and I dig that level of play too.

Spending dice from the pool to add complications, assets, or scene distinctions is fantastic. You can boost NPCs on the fly or even encounters.

  • D8 everything is ablaze, or poison gas released

  • D10 booby-trapped!

You also could go from:

Undead skeleton mob 3d6


Undead skeleton mob 3d6

+ D8 unholy aura (from Doom pool)

Nothing new here I’m ticking off all the positives for using a Doom Pool in my West Marches 2.0. Easier prep work, easier facilitation, and fictional opportunities make for a strong must-have list.

Play Fearless!