Chained Worlds: Deep Carbon Observatory

In almost two years DMing for the same group, I’ve used two pre-written modules. The first time, it was a short-notice replacement session, so I ran an “official” module, Death House, because it was free and on hand. This time, I ran Patrick Stuart & Scrap Princess’s Deep Carbon Observatory. I ran it because it’s weird and scary and flexible. Here are some changes I made, some things that happened, and some thoughts I had.

– I run two groups that are all members of the same organization. They each meet every other week, but every two months, everyone’s invited to an all-team session.

– It’s very much a “drop-in” environment. Each group has five or six people, and as long as at least three of them show up for any given session, we play. Most sessions last about three hours, and I try to get a lot wrapped up by the end so that people who missed the session don’t have to start in the middle of things the next time they show up.

– Half of my players have never played D&D before we started this campaign in May 2016. The other half played in a 1.5-year campaign I ran. Only one has played D&D as, like, a lifestyle.

– Both of my groups are from Carrowmere, the city in Deep Carbon Observatory (which is actually called Carrowmore in the book, but I misread it). One group has already visited the top of the dam that plays a key role in DCO; there, they met a potential ally who’s opposed to the organization they work for.

– They’ve done some work for the observatory church of the Optic God and its Eyeball Pope, so they’ve heard rumors of another, more ancient telescope…that looked down instead of up.

– The players often talk their way through encounters. Failing that, they fight. They haven’t had much experience with a classical dungeon environment where things are arbitrarily deadly.

This last point had some very real consequences.

So I wanted to run Deep Carbon Observatory as one of the all-day, all-team sessions. I knew I’d have to make some changes—there’s enough content in DCO for months of weekly play. So if you’re familiar with DCO, know that I’ve eliminated…

– most of the flowchart of Carrowmere encounters
– a few sites on the way to the pit
– a handful of chambers in the dungeon
– and most sadly, the Crows

The first three items were removed to save time. The last one was removed because I wasn’t confident that I could DM them properly—I wasn’t sure that I could keep track of their strategies and do credit to their personalities.

Even with a third to half of the content removed, DCO still took three sessions to get through. And, as we’ll see, the players didn’t even make it through the full dungeon. Here’s a breakdown of the highs and lows:

Player Successes
The ranger used her magic (and roleplaying) to make a deal with a trapped giant eel. I was constantly ready to have the eel turn on them, but they were consistently careful and gracious, so they had an eel buddy for a day.

The warlock saved a bunch of orphans…and promptly took them to live and work in his creepy temple.

Due to some excellent tactics and the paladin’s sacrifice (see below), they found the treasure room without much conflict.

The warlock chopped the cursed thorium tongue in half, avoiding its danger! Until he didn’t. But when his tongue was replaced, he changed his character voice and soldiered on.

After leaving the dungeon, the players had a lengthy in-character conversation about their biggest fears and failures.

DM Successes
The floating brains in the canopic jars were suitably weird and cool. The players loved the regret-or-paralysis mechanic.

The giant was scary and gross. It reached through tiny tunnels to slam people against walls and then ran off when it took damage. There ended up being three discrete battles. In the second one, the giant braced himself between the dungeon’s stalactites, reaching into the salt dryad chambers (previously befriended by the players), and tossed the chemical women at the players besieged on the bridge below. In the last encounter, it almost threw the warlock out into the abyss. In its death, it blocked their way home, so they had to chop it up to proceed.

The thorium tongue! I kept it creepy, so the players chopped it in half. Trap avoided? Nope, the dragonborn warlock decided to eat it once it seemed “dead.” I asked if his tongue was forked. He said yes, so the cloven thorium tongue had to replace it (of course). He rolled a 1 on his save and ripped out his god-given tongue. Now I get to interrupt his spells and attempts at diplomacy with Exorcist-style swearing and cursing.

Player Failures (or rather, things that went bad for them)
The paladin died, eaten by a snake door. See below for how I wish I’d have handled it.

The dragonborn warlock ate a cursed tongue.

DM Failures
I didn’t play the witch as well as I could have. She did manage to charm the paladin and KO the wizard, but she was promptly killed by a powerful 5E magic missile. I should have upped her HP.

The paladin died. He put his hand in a snake door, which hurt but didn’t kill him. He told everyone to let him be eaten by the door, and the party obeyed his wishes. Could I have made this more ominous? Should I have allowed him a save despite his desire to be eaten?

The players decided to leave the dungeon without finding the actual observatory. I think they were bored or tired of the environment. I could have used their time on the bridge to better entice them toward the bottom of the main stalactite where the telescope is kept.

Luckily, they relayed their findings to their ally on the dam, so he can go down there and tempt them back with descriptions of his discoveries and his new views on drow psychology…

Scrap Princess artwork from Deep Carbon Observatory

DCO is an excellent module, so thank you to the authors. Even if someone didn’t want to run it, its perfectly lootable for encounters, items, history, and more. Buy it here.

The players in my group might never use the Observatory to look down through the chain of worlds, but they’ll forever be from Carrowmere, and the Optic God is still watching them.