Cepheus Engine
SRDA free 2d6 sci-fi engine built on the bones of classic Traveller
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Languages: English
Dice2d6
System FamilyTraveller
CostFree
LicenseOGL
PublisherSamardan Press
Year2016
Complexity
Medium
Accessibility
High
Community
Medium
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.
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.
Highlights
Completely free and OGL, large third-party ecosystem, comprehensive rules covering personal combat to starship design, fully compatible with classic Traveller material
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