Cepheus Engine vs The Expanse Roleplaying Game
Compare Cepheus Engine and The Expanse Roleplaying Game side by side. See differences in complexity, dice, genre, cost, and more.
| Cepheus Engine | The Expanse Roleplaying Game | |
|---|---|---|
| Genre | Scifi | Scifi |
| Tags | Sandbox, Modular, Toolkit, Simulation | Licensed IP, Space Opera, Ship-Based, Crunchy, Social Combat, Investigation, Faction Play, Social Intrigue, Strong GM Support, Tactical |
| Core Mechanic | Roll 2d6 + skill level + characteristic modifier. Meet or beat 8 to succeed. Effect (margin above/below 8) determines degree of success or failure. Lifepath character creation with careers, skills, and mustering-out benefits. | Roll three six-sided dice, two matched and one differently colored Drama Die, and add an ability score plus a focus bonus of +2 if applicable. The total must equal or beat a target number set by the GM or an opponent's result. Rolling doubles generates stunt points spent on combat, exploration, or social effects. The Drama Die's value sets the degree of success. |
| Dice | 2d6 | 3d6 |
| Complexity | Medium | High |
| Accessibility | Very High | High |
| Runnability | High | Very High |
| License | OGL | All Rights Reserved |
| Third-Party Publishing | Not yet researched | No verified route found |
| Summary only, not legal advice. Check current terms before publishing. | ||
| Cost | Free | $$ |
| Publisher | Samardan Press | Green Ronin Publishing |
| Year | 2016 | 2019 |
| Languages | English | English |
| Best For | GMs who want a fully open, hackable classic sci-fi engine for sandbox campaigns: trade, exploration, and space combat without any IP restrictions. | Groups who want a character-focused science fiction campaign of crew jobs, faction pressure, and danger across the Solar System. It suits tables that want structured action, investigation, and social encounters alongside ship travel. |
| Highlights | Completely free and OGL, comprehensive rules covering personal combat to starship design, fully compatible with classic Traveller material | Backgrounds, professions, talents, and focuses build characters with mechanical ties to their lives before the campaign begins. Action, exploration, and social encounters each use dedicated stunts, giving different kinds of scenes procedures beyond a single skill roll. The Churn turns accumulated complications into escalating story events, giving the Game Master a structured way to introduce setbacks. |
| Considerations | Dense 200+ page SRD with no setting or adventure content, lifepath character creation can kill characters before play, assumes GM comfort with sandbox prep | Combat stunts are drawn from six separate category tables covering roughly sixty options, requiring both players and the GM to check charts mid-fight to keep pace. Ground and air vehicles receive no example statistics, leaving their combat rules almost entirely improvised. The forty-page setting guide summarizes the solar system's factions and history at a survey level, so groups wanting deeper political detail need outside reading of the novels. |