The Expanse RPG Review, Part 2

We’re back today to wrap up our look at The Expanse RPG by Green Ronin. Last time I looked at character creation and what the game looked like compared to the Modern AGE RPG that it’s based on. I’m not the first to compare them by any means, but I’d rather focus on the unique elements of The Expanse itself. That’s why I’m happy to delve into the heart of the setting and how GMs can craft a story worthy of the original.


Let’s start, as the book does, with the basics. When you accelerate, you experience a force whether you’re in a car that’s slowing down and your pushed forward, in an elevator that’s climbing and you feel pressure on your feet, or you are falling due to gravity and feel a pull towards the ground. Acceleration means a change in velocity (so-called ∆v) and your body (as well as objects you hold and food you’re eating) doesn’t know the difference between any of these situations. That means you can be on a spaceship that is speeding up towards its destination or slowing down to stop there and you will perceive “artificial gravity” pointing towards the engines. You also experience forces when the ship is turning and when you are launching through space, especially with the superfast Epstein Drive.

Image © Green Ronin

This is important part to wrap your brain around because I’m a science teacher and I said so… Also because it’s constantly coming up in the series: Belters will complain about hard burns, people are thrown to the side and/or injured by sharp maneuvers, and the enemy outpaces you because their engines are better and their anti-aneurysm drugs can handle more Gs. There’s several very helpful pages in the book covering things like escape velocity, apoapsis and periapsis, gravitational spheres of influence, prograde and retrograde motion, and brachistochrone trajectories. It also has a bit on lightspeed communications and the general lags in communication between planets, not to mention the travel times for ships at .3G (Martian gravity), 1G (Earth gravity), 7G (hard burn), and 12G (really hard burn). There aren’t a lot of game mechanics in this section but it really makes it easier to talk about this and answer player questions on the fly.

For ships themselves, they follow similar rules for vehicles found in the Modern AGE core book but with a lot more detail to make them unique and particular to their crew. Ships have a Size rating which ranges from Tiny (5 meters long) to Titanic (a kilometer or more long… basically the Nauvoo), and that determines their Hull (like a character’s Toughness) and crew size. They also have Drive ratings (how fast they can burn), Sensor ratings (added to rolls for scans), and Weapons listings (grapplers, PDCs, rail guns, and torpedoes). They have Qualities and Flaws just like characters as well so you can modify and personalize a ship for your PCs, just like the Rocinante.

There are some smallish ships listed (shuttle, ship’s boat, and drop ship) and then a civilian and military option for each size from Large to Colossal (nothing provided is actually Titanic). This gives eight different ships for your players to crew, not counting those first three, and it allows you to easily make them a military outfit (or paramilitary like the main characters of the series) or a civilian one.

Image © Green Ronin

An important question that I’m sure a lot of you have is how spaceship combat works. Well, the bad news is that it’s a multistep process with new steps that different from personal combat or other pre-existing parts of the game. The good news is that it’s pretty straightforward and dynamic. First the character in command of the ship Commands, generating stunt points that can be used on specific benefits. Then the pilot engages in some Maneuvers and the comms person uses Electronic Warfare to jam the enemies targeting sensors (defensive and offensive bonuses). Then there are Weapons Attacks and Defensive Actions, including PDCs, followed by Attack Damage. After that there’s a chance to use Damage Control to mitigate the effects of the damage. It’s all really too much to summarize here (though keep an eye out for a future post) but there’s a breakdown of the attack on the Protean base from the first book (or second season) that helps you parse it all.

Future History

I’m not going to get too much into this to keep the surprise alive, but basically the default time period here is directly after the first book and midway through the second season (as far as Episode 5). I think this is awesome and actually more satisfying than Green Ronin’s other franchised product line, A Song of Ice and Fire Roleplaying. While it makes sense to start things before any of the narrative takes place, as SIFRP does, this means that fans (the ones who are most likely to pick the game up) have to forget about all the cool stuff they already know. Instead, setting things partway into the series lets you use some of what you like while not making it prohibitive to new players.

In this section is a profile for Chrisjen Avasarala and an overview of the major political powers of the day, as well as a little something called the “protomolecule” that’s making everyone crazy at the moment. It’s a good bit of background to get you up to speed.

Image © Green Ronin

Earth, Mars, the Belt, and the Outers

While Chrisjen appears in the previous section, these three chapters outline many of the major players and discusses the setting as a whole. The structure of the UN, the Earth and Martian Navies, Belter Creole and sign language, societies of all three cultures, and relations between them. Various important cities and locations are outlined, complete with plot hooks, and colorful quirks to use in your background. And there are even locations not yet seen on show or in the books for your crews to visit including Callisto, Rhea, Titan, the Uranian system, and the Neptunian system. Profiles and stats can be found for James Holden, Amos Burton, Alex Kamal, Bobbie Draper, and Naomi Nagata.

Game Mastering

This section mirrors a lot of what’s in the Modern AGE core rulebook, though it has examples and context for games in The Expanse setting. Hacking a computer system, infiltrating a gang, and breaking into a secure facility are given as examples of challenge tests and each of them should make you envision an Expanse story. A bigger expansion of the rules is the Churn which is health, luck, and Fate all rolled into one. The Churn Pool starts at zero for each new adventure and a point gets added every time someone succeeds with a 6 on a Drama Die, overcomes an encounter or hazard, spends 4 or more stunt points on a stunt, alters a roll with Fortune, or completes a section of an adventure.

Basically, if the player characters are having it too easy, this ramps up the pressure. When the Churn Pool reaches 10 points you roll to see if something happens, and when it reaches 20 something definitely happens and you roll to see what. If it reaches 30 things really go bad and it resets to zero. This section continues with social encounters, combat tips, guidelines for creating adventures and (in another chapter) whole series, dealing with canon, and running a smooth game. It’s all great advice and I found myself getting excited for all the great GM tips even beyond The Expanse.

Image © Green Ronin


This chapter is split into two parts: hazards and adversaries. Hazards are, unsurprisingly, environmental factors that threaten the crew. A number of different hazards are detailed, all of them great for the setting and tone: acceleration, exposure (to harsh environments), gravity, illness, toxins, radiation, impact (slamming into stuff), starvation, dehydration, and vacuum. In addition to these somewhat common hazards is, of course, the protomolecule which is horrific and incurable. Don’t get infected with this stuff.

Following the hazards come the adversaries. These NPCs come in five different levels (just like in vanilla Modern AGE): Minor, Moderate, Major, Dire, and Legendary. Notes are given for creating adversaries, improving adversaries, how to interpret the level of socially-focused adversaries, and supporting cast members. A host of sample adversaries rounds out the chapter with a bounty hunter, combat drone, gang boss, hooligan, pilot, pirate, police detective, police officer, saboteur, soldier, security guard, spy, thug, and veteran. Unusual (read: protomolecular) adversaries also appear with the vomit zombie and Project Caliban hybrids. If you don’t know what those are, don’t worry.


What do player characters get for their efforts? Well, they can get paid, of course, and Income is a good way to improve the characters’ gear, ship, and lifestyle. They also get reputation boosts including honorifics like “the Butcher of Anderson Station” which give further bonuses when they become relevant. There’s also Membership in groups like the OPA, miner’s unions, or Navies and there are relationship bonds that can build with PCs and NPCs alike. GMs certainly have a lot of tools in their boxes to keep up that feeling of progression and only one of them is about “leveling up” in power!

Image © Green Ronin


I expected a lot from this game and it did not disappoint. The tone is very on point and there’s plenty here to get you started in a game of The Expanse. The only stuff that’s missing is the rules for later setting elements, but Green Ronin has been repeatedly saying those will be in future supplements (something I’d love to see for SIFRP if you’re reading, Green Ronin staff!). If you love the books, the show, or both this game will certainly give you the avenue you need to play in James S.A. Corey’s world of gritty sci-fi and existential horror. Enjoy!

7 thoughts on “The Expanse RPG Review, Part 2

  1. Thank you, been waiting for the part 2 since you post the first one, after all your post i will definitely buy the game to dm for my friends.


    1. Glad it was helpful! I try to space things out a bit but if you’re ever waiting on something again just leave a comment and I will bump it up in the queue if possible.


  2. Thanks for the reviews. I saw that the PDF was available this morning and this helped Green Ronin get a sale. I’ve read all the books and shorts and seen all the episodes so far, so really been looking forward to this.


    1. Glad to help! I don’t expect everyone to like everything I review, that’s why I lay it out like this. However, I think if anyone even remotely likes The Expanse (book or show) they’ll love this.


  3. Thanks for your article! I am looking forward for more updates on the Expanse. Soon, I am about to GM the quickstart with a fresh group. I am excited to see how it develops! And I hope that we’ll continue with more quests. Can’t wait!!


      1. Thanks! we finally found the time to give it a try.
        We completed the quickstart with five characters and it took us about five to six hours (with the usual in between food). Our story had a somewhat darker ending than expected, but overall, it was very fun and easy to get into. Most of the players had zero to very basic experience in Pen&Paper RPGs and the quickstart was the perfect entry. Our game was lacking some ACTUAL role playing, but I think it’s always better to stay in character if you created him/her yourself. So, i cannot really blame my guests. What I really liked about the Expanse quickstart is that it leaves the GM and the players a lot of empty canvas and options to go along. The basically three to four different interest groups help to develop an own plot along the play. My guests were developing their own theories and allies(?) along their way. If you give their play the breath it needs, the story can go into all different directions. The easy to understand and executable test system doesn’t stop the flow and works pretty well (I GMed worse systems).
        The only issue that I had with the rules was the amount of stunts the players could do. So basically, every time you roll doubles or every time an attack succeeds, you earn stunt points (i.e. number of the “charm dice”) that you can spend on additional actions etc. For instance, dealing an additional 1d6 damage. Personally, I would reduce the events where you generate stunt points. I believe, you could leave them out when an attack succeeds and only gain them when you roll doubles. But this is the only issue that we faced (well and maybe the generic casual thug was a bit too strong).
        So overall, we had a pretty good time and both sides enjoyed the quickstart – GM and players. I plan to buy the full rule set and I hope that we’ll have more adventures around the belt and maybe beyond(?). This time, with proper characters and more appealing back stories. I am looking forward for more news around the Expanse and co.

        Liked by 1 person

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