Cepheus Engine
SRDBest For
Groups who want interstellar sandbox campaigns built around trading or exploring aboard a shared ship.
Core Mechanic
Roll 2d6 and add the relevant skill, characteristic modifier and difficulty modifiers. A total of 8 or more succeeds. The margin above or below 8 is the Effect, which determines the outcome where the rules call for it.
Most tasks use the same 2d6 check against 8. Career generation and combat add distinct procedures to learn. Ship design connects operating costs and cargo capacity to travel and trade. The referee must coordinate these systems with generated worlds and encounters.
- Free to tryFull core rulesLegally free as an SRD, PDF, or official web rules
- Get it nowAvailable nowFree to download or read online
- ✓IndexFind any rule by page number
- ✓GM guidanceA chapter on how to run the game
- ✓Examples of playRules shown in action at the table
- ✓Quick referenceCheat sheet or summary tables
- –Cross-referencesRules rarely point to each other by page
4 of 5 book tools found in the core book
Highlights
Career terms generate experienced characters whose skills and starting assets reflect their prior lives. Planetary trade codes modify cargo prices, giving merchants a reason to compare routes and markets. World and encounter tables provide the referee with material for an interstellar sandbox.
Considerations
Failed career survival rolls kill characters by default, with an optional mishap alternative requiring referee approval. Damage reduces physical characteristics, weakening injured characters until they recover. Operating a ship requires tracking recurring expenses alongside its income.
Third-Party Publishing
Rules license Open Game License 1.0a
Reuse and adapt designated SRD rules under the OGL, excluding Samardan Press product titles and trademarks. Compatibility statements use the separate CSL.
Include the OGL, required copyright notices and identification of Open Game Content. The CSL requires trademark attribution and non-affiliation notice; modified standalone games need a cover disclaimer, and effectively unchanged copies cannot be sold under the CSL. Traveller settings and trademarks are not granted.
Similar systems
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- Diaspora — Hard science-fiction across a cluster of slipstream-linked star systems the players build togetherCompare Cepheus Engine vs Diaspora