There’s nothing quite like the look of dawning horror on a physics PhD’s face when you tell them their characters have landed on an asteroid that’s 18 kilometers wide with light atmosphere and near-normal gravity. That moment at my GenCon table perfectly captures what makes Coriolis: The Great Dark such a compelling experience. It takes you to places that shouldn’t exist. These places are powered by ancient alien technology and wrapped in half-million-year-old mysteries.
A New Direction for Coriolis
Players familiar with The Third Horizon will recognize the universe. However, The Great Dark needs to be approached as its own world. It is a separate game. Free League has crafted something with a distinctly different tone and emphasis that’s completely accessible to newcomers. You don’t need prior Coriolis knowledge to dive in—though existing fans will certainly appreciate the deeper world-building context.
This isn’t high heroic fantasy. If you’re looking for that, check out Dragonbane instead. The Great Dark is fundamentally a resource management and investigation game. It draws inspiration from 19th-century expeditions, deep-sea diving, and pulp archaeology. It is built around five core themes that the book explicitly calls out: Exploration driven by necessity rather than adventure, Intrigue within the conspiracy-riddled Ship City, Mystery surrounding the vanished Builders and their artifacts, Hope that drives you to help civilization survive against the odds, and Teamwork as an absolute requirement for survival.
You play as members of the Explorers Guild, the newest guild tasked with investigating Builder sites that might hold the key to saving the Diaspora. Armed with a Garuda, commonly referred to as your Bird,—a construct whose true nature remains mysterious—you’ll brave uncharted depths and face unspeakable horrors in humanity’s desperate search for answers.
The Delving Rules: Atmosphere or Grind?
The heart of the game lies in its delving mechanics, which remind me strongly of the Journey rules in The One Ring 2e. Like those rules, they can either create incredible atmosphere and suspense or devolve into a tedious grind of dice rolling and event management. The difference comes down to execution.
When done well—which I’m still working on mastering—the delving rules slowly wear down characters and their precious Supply before they even reach the main adventure site. The resource management creates genuine tactical decisions: which team member can afford to be reduced? In what order should we explore areas while ensuring we have enough Supply to get back to safety?
The tricky part as a GM is ensuring player agency and engagement, making each roll feel impactful rather than arbitrary. At GenCon, I saw this dynamic play out in real time. The players had mixed reactions to the mechanics themselves, but they absolutely loved the resource restrictions and the meaningful choices they created. Some were willing to push their luck more than others, leading to interesting tactical discussions rather than interpersonal drama.
A Living, Breathing Universe
What really shines in The Great Dark is the world-building. Every area in Ship City and every outpost in the Lost Horizon comes with detailed background and hooks that will provide years of gameplay even if nothing else is ever released. The book gives you a complete sandbox to explore, with the ruins of this vanished civilization and their ice-like Blight as central mysteries that explain the impossible while raising new questions.
The Bird isn’t just equipment—it’s both tool and character with real agency. There are three main types: Ward Birds emphasizing protection and combat, Guide Birds focused on searching and scanning, and the rare Specter Birds that can interface with other creatures’ minds. The Bird is your delving team’s most important asset, capable of detecting the terrifying Blight, protecting the crew, and mounting attacks when necessary.
Production and Practical Concerns
The book itself maintains Free League’s top-notch production standards, featuring beautiful art by Martin Grip and maps by Christian Granath and Francesca Baerald.
However, like many Free League games, finding specific rules on the fly can be challenging during play. I strongly recommend having the PDF on a tablet for quick lookups, though honestly, when in doubt, make a ruling that feels right, check with your players, and keep the game moving. Don’t let rule-hunting break your flow.
The game works best with 4-5 players plus a GM. The mechanics and resource management are designed around that sweet spot of team composition. I’ve run it with six players, and that sixth person definitely becomes the odd one out.
Who Should Play This?
The Great Dark appeals to players who enjoy tactical resource management. It attracts those who love investigation-focused gameplay and slow-burn exploration. In this exploration, the journey is as important as the destination. If you’re drawn to mysteries that span geological timescales, civilizations on the brink of collapse, and the kind of ancient alien artifacts that make physicists question reality, this game will hook you hard.
However, if you prefer fast-paced action, high fantasy heroics, or games where you can reliably succeed through bold action alone, The Great Dark might not be your cup of tea. The delving mechanics require patience and buy-in from the entire table to really sing.
Final Verdict
I am genuinely excited to run more sessions of The Great Dark. I rate it a solid 4 out of 5 stars. It’s a strong game with a clear vision that executes well on what it’s trying to do. That missing star comes from the reality that the delving rules won’t appeal to everyone—they require a specific kind of engagement that not all groups will embrace.
For those willing to embrace the slow burn of resource management, The Great Dark offers something genuinely special. It includes the thrill of archaeological mystery-solving in a universe where ancient secrets might save or doom humanity. It’s exploration not as adventure, but as a desperate necessity, and that makes all the difference.
I’ll be running The Great Dark at Gamehole Con, so if you’re attending, come check it out in person!
Want to Experience The Great Dark? Interested in trying Coriolis: The Great Dark? I’m available for online or in-person gaming sessions. Whether you’re a curious newcomer or a veteran looking to explore the Lost Horizon, let’s delve into the mysteries together.
Next time, I’ll dive deeper into character creation and what makes building an Explorer so compelling. Stay tuned!