Running DCO: Roads not taken

11 Sep, 2025

NOTE: This post will contain spoilers for the module Deep Carbon Observatory by Patrick Stuart and Scrap Princess.

Three sessions into Deep Carbon Observatory and I’m already trying to think about what I’d change.

This isn’t the module’s fault. I think many GMs are inveterate tinkerers, and the more we like something, the likelier we are to take it apart to figure out how to make different aspects align more closely with our sensibilities and priorities, as well as the sensibilities and priorities of our players.

One consistent piece of feedback I’ve gotten while running DCO is that the premise is in tension with some of the situations in the module. As written, the module after the opening sequence (which I’ve talked about how I’d run differently here) is a series of location-based vignettes interspersed with encounters. It’s evocative and interesting, but the PCs have very little incentive to actually interfere with most of these. The crab windmill is a great example — it’s incredible imagery, but going there doesn’t accomplish anything.

Part of the issue is that the dam bursting is only a tragedy on paper. As written, the PCs in the module are tourists arriving on the scene and seeing a bunch of horrific stuff playing out, with no sense of how to make things better. That’s fine, and somewhat realistic — I doubt I’d be much use if a natural disaster landed on my doorstep tomorrow.

What’s jarring and seems to take at least one of my players out of the game is the disconnect between the characters and the NPCs. “Here’s the village headwoman being yelled at by a group of rival adventurers.” “Here’s a priest losing his marbles as he watches smoke peel off the dam from the roof of his church.” Beautiful images, but very little substance for the PCs to dig into. (Some of the locations on the river feel like this as well.)

This is the natural outcome of starting a module in media res with strangers rolling into a town devastated by a natural disaster. The key to making things more organic and providing players with clearer stakes in the events transpiring is to turn the clock back and spend a few sessions in the Lock Valley before the dam bursts.

If I ever run DCO again, I’d transform Carrowmore into a hub location for a small sandbox dotted with dungeons containing minor treasures of the dam builders. I’d sprinkle in interactions with the NPCs who appear in the opening sequence and allow players to study the language of the dam builders and try to puzzle out what exactly happened upriver before bringing down the dam and sending the world into chaos.

DCO is intended for higher-level parties, so you could even wind the clock back further, starting a campaign with the PCs journeying to Carrowmore and finding more eccentric dungeons and esoteric treasures as they near the town. It’s easy to imagine leading a trail of breadcrumbs from the campaign’s starting location up to Carrowmore and the dam beyond it.

The key flaw I see with this approach is that it probably robs DCO of much of its moral ambiguity and nihilism. Part of the horror is roleplaying as bystanders with very little say over what happens, who lives, and who dies, much less the context to understand the full ramifications of that decision. Is helping a widower carry his dead wife to her tomb more affecting if you’ve spent hours learning about their life and their marriage, or does the sequence work better as a moment of altruism on the part of strangers caught in awful circumstances?

I don’t think there’s a correct answer, though I know what my answer is.