Omer G Joel over at has been posting about his new background for the Cepheus Engine (a kindof Traveller retroclone mostly compatible with Mongoose Traveller), and it sounds fun, especially the aspects that lend themselves to aliens/outland style horror. I’ll note that it’s not the only project to do “weird shit man was not meant to know in space” of the gritty variety, there’s also a project called “Hostile”

From his latest posting on interstellar travel:

  • Interstellar travel uses the Jump Drive. The jump drive is a complex contraption manipulating an Antediluvian artifact – a Spindle – to punch a transdimensional between real space and the alien realm called Jump Space. The complexity and size of the drive determines its capability to manipulate its Spindle, hence the different jump rates.
  • A jump is approx. 7 days in length and transports the ship one parsec per jump number, as in baseline Traveller.
  • Unlike baseline Traveller jump drives, Hard Space jump drives do not require fuel, only energy input from the power plant. However, after a jump, the drive requires time to “spool” and recharge. This time is 1D days minus the attending engineer’s skill, to a minimum of one day.
  • Jump drives require a gravity well on both sides. A small brown dwarf is sufficient. There are no “empty-hex jumps” or “calibration points” – you need a star on both sides.
  • Jumps can be inaccurate. The higher the ship navigator’s throw when plotting the jump, the closer to its destination the ship emerges. An unlucky navigator might find their ship in the outer system, while a skilled or lucky navigator might emerge directly into orbit of the target world. Ships do not emerge within large masses or very close to them – so there is no risk of emerging inside a sun or planet.
  • Misjumps are dangerous and can result in encounters with the Unknown and insanity. This is messing with barely-understood alien technology and parallel dimensions which defy too many rules of physics. A good jump throw avoids most of the unpleasantness, but a misjump exposes the crew to all sorts of nastiness. Beware.

Other, earlier posts detail how interplanetary travel works, etc., in the setting.

Me, I’ve got the entire classic Traveller rules including expansions, deck plans, Fifth Frontier War, all of it, on CD, and I’m still likely going to grab the Cepheus rules.