The New OSR: The case for the Cepheus Engine

First of all, do we need a new OSR? 

No, of course not. There’s no shortage of people still creating, playing, or just discussing D&D-style games, with oceans of interesting material available. Also, I’m not going to quibble over the definition of the OSR, or whether it’s “alive” or “dead”. A lot of photons have already been spilled over that. For the purposes of this post, I’m treating the term “OSR” as just a loose community of people all creating things based around a somewhat D&D-compatible or D&D-inspired set of rules.

My argument here is that there’s a lot of room for designing interesting things using a different core system, specifically the Cepheus Engine. My goal is to encourage others to start creating gaming stuff based around Cepheus.

What the hell is the Cepheus Engine?

Basically, it’s Traveller – a science fiction RPG from 1977, one of the first successful RPGs. It’s gone through multiple editions ever since. The Cepheus Engine is a open-source RPG system using essentially the same ruleset. You can see the basic SRD for free here. It’s got an OGL license, so you can use it to create anything you want.

There are many RPG systems, including many free and open-source ones. Why use the Cepheus Engine? To answer that, I’d ask what features a game would ideally need to be core of an OSR-style community

What things does a new OSR need?

An Open License

A OGL-style license isn’t probably 100% necessary, but if you want of a community of designers to actually make stuff., it’s a really good idea. The original Cepheus Engine was created when Mongoose, who has the current rights to Traveller, decided to stop using the OGL license.

The Cepheus Engine was originally created in response to this. Every version of it has been completely open-source. You can make a Cepheus adventure, supplement, or even an entire RPG with no legal wrangling required.

Deep History

There have been over 40 years of Traveller supplements and adventures (and about 6 years of Cepheus stuff). Why should that matter? There are two reasons:

First, there are decades of Traveller rulebooks, supplements, and zine articles to steal ideas and mechanics from. Whatever idea you’re trying to develop, there’s a good chance someone’s already done something similar that you can use as inspiration. Great artists steal.

Second, any game needs players, and there’s already a lot of gamers who play or have at least tried Traveller. It’s obviously not at the same scale as D&D, but you’re not starting from zero.

You don’t need any of these, but they might be useful.

Easy to Run, Easy to Hack

“Official” Traveller has been through several different versions, from several different companies. Though there have been many editions, with new rules and subsystems, the basic system is simple, solid, and hasn’t changed in decades. In short, Traveller has good bones. 

If you’re not familiar, the core mechanic in both Traveller and Cepheus is a simple 2D6 roll. You add the value of any applicable skill, and possibly a stat bonus. You’re trying to hit a target number or above (usually 8+)

There are no levels or classes, and instead of hit points, damage goes directly to a character’s stats.

Different versions of the system will add more details and subsystems, but the heart of the game hasn’t really changed. A Traveller GM from 1977 would have little trouble running the Cepheus Engine. The simplicity of the core rules makes it lot easier to experiment with, and to tinker around with your own custom rules. 

Since a 2d6 roll makes a nice little bell curve, the system isn’t particularly swingy, and you could argue it’s well-suited for “realistic” games – low powered, grittier games. Hard SF (obviously), modern action or espionage games, or Conan-style low fantasy.

A Community

Most importantly, the community for the Cepheus Engine already exists. There are multiple companies already producing commercial works for the system, a lot of free online stuff (here’s my stuff), and an excellent fanzine – The Cepheus Journal.

A few of the bigger Cepheus systems


What I’d like to see, is a growing Cepheus Engine-based design community. To some extent this already exists, but I’d like to see more. has a lot of D&D style stuff, but not a lot of Cepheus stuff. 

What I’m hoping for Cepheus, is to see the wide variety of pro and amateur stuff we see for D&D OSR games – zines, alternate rules, settings, etc. 

I’ll probably post a few more things on this subject. The next post will be quick survey of the various flavors of Cepheus, and what I think they’d be best used for.

Then, I’ll follow my own advice and make a few posts designing (or partially designing) actual CE-based games.

If any of this sounds even a little interesting, I’d suggest taking a look at the basics:

You can see the free Cepheus SRD here:

Or get a free version of Cepheus Light ( a much simpler version of CE):

All my Cepheus Engine as New OSR posts

12 thoughts on “The New OSR: The case for the Cepheus Engine

  1. There’s so many good Cepheus Engine genre hacks but I’d love to see something that really stretches the engine to the realm of Supers. (I’ve seen Michael Brown’s 2d6 Powers but that only scratches the surface.)

    Liked by 1 person

  2. And then there are the folks to whom “OSR” means any old-school game, in which case we already have a Traveller OSR. I’d also like to mention the fine folks at Cthulhu Reborn, who have been releasing their Cthulhu Eternal OGL SRDs. Also there are a lot of variants uploaded to BRP Central, where you can find things like a W40K RPG and Middle-Earth RPGs:

    Liked by 1 person

    1. It’s not my preferred system, but a lot of of the points I’ve made about Cepheus also apply to the whole BRP world.

      It’s got a long history, lots of games, and a lot of people have at least played CoC. Definitely a solid choice for designers.

      Liked by 1 person

  3. I could not agree more, and for a while now have been tinkering with a CE/Sword of Cepheus inspired Atlantis myth-based hack (notionally called Antikythera Mechanism). Maybe I’ll get inspired to revisit it now…

    Liked by 1 person

  4. I’ve crossed paths with Traveler since the 1980s but aside from the occasional convention game have never really taken the plunge. Aside from SF, which genres would you say that the system is best suited for?


    1. I think anything low-powered works best. Low fantasy (Conan style), historical games, modern action/espionage games.

      Cepheus can work in other, puliper genres, but probably requires a little more tinkering.


  5. One of the things about many systems that I don’t like is the book-keeping aspect for hitpoints or similar stats on the GM side. This is always okay for one on one combat, but when the GM as multiple enemies it is annoying. Is there a “threshold” style hack for this system similar to how Savage Worlds handles NPC damage so there is no hitpoint style tracking for the GM?

    For me I wish more systems would have the GM in mind when creating their rules and come up with more streamlined style mechanics.


    1. The base SRD doesn’t, but some of the newer ones like Cepheus Deluxe do have a “Heroes and Grunts” optional rule.

      If that rule is used, any damage that penetrates a NPCs armor takes them out of combat. No bookkeeping required. Quite similar to the Extras rules in Savage Worlds.

      This rule is clearly intended for pulpier Star Wars-style games.


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