I have a bad habit of writing variants to games - as you may have noticed. Usually these amount to nothing (my Civilization board game variant), but occasionally they result in large design documents (my Civilisation Revolution expansion) or actual implementations (Unangband, UnBrogue).
My High Frontier Interstellar variant rules have made the jump from the design document phase to implementation, and hopefully will be included in the upcoming Kickstarter. Phil Eklund, the designer for High Frontier, had seen me active on the forums and liked some of the design suggestions I had made. He contacted me on April 18th this year with some comments in the Google document to the effect he was looking at including my variant rules in the 3rd edition of High Frontier, and that I had a week (!?!) to play test the finalized changes and come back to him with additional feedback and recommendations.
The actual development process has run through to the 13th of June as I've made minor tweaks and clarifications to the rules, although the vast majority of changes were made during that initial week. I've got an email from Phil dated the 24th where he's obviously worked late at night to include my rule revisions into the poster map available on Zazzle.
High Frontier Interstellar is primarily a solitaire game (with two highly experimental multiplayer rule sets in the 3rd edition) which uses the components including patent cards from the main High Frontier game, but has its own rules and map board available for purchase as a poster (be sure not to buy the postcard size version of this poster by accident). It achieves this by reusing statistics, symbols and some rules from the High Frontier patent cards, along with a small number of additional card features highlighted or surrounded in green to indicate they are specific to or also apply to the Interstellar rule set (piloting and terraforming symbols, starship engine thrust and fuel consumption figures and some robot colonist special abilities.)
Thematically, Interstellar is the shot for the stars following the colonization of the solar system modeled in the High Frontier game. You are responsible for managing the crew and would be colonists as they travel in a star ship fraught with risks: each 12 year turn you roll a ship event dice which indicates what risks each passenger career suffers - with up to 4 out of 6 face rolls causing a potentially deadly risk for some careers. You can minimize risks and suspend aging by putting passengers into the vats, but they're otherwise careerless while in the vats so don't get any actions, and have to go to school for 12 years when they exit the vats to earn their new careers (with the attend risks of a ship event roll).
Each passenger with a career can perform one or two operations each turn: the career counters indicate which actions they may select from, the symbols on the cards indicate which careers they may learn at school, each career comes with its attendant ship event roll risks and a list of operations it may perform. This is summarized in the career track on the poster map in a graphical form, part of which is below:
A typical risk resolution is Cancer. Roll 1d6 < the card's Age (number of turns in the game) and the human passenger dies, except if you've successfully researched the Cure Cancer Breakthrough, where you get to roll 2d6. Given that you rarely have more than one alert scientist on the ship, and the difficulty of succeeding at finding this cure is also dependent on their age, you can see how deadly Cancer can be if you are unlucky enough to roll it.
High Frontier Interstellar is a game about balancing risks. There are high risk careers like scientists, and space walkers, business and engineering, and low risk careers like pilot, and domestics, and biotechs, but the careers are there primarily to manage the accumulating risks of age, stress, political differences in the crew, technology run a muck and the comparatively easily managed risks of micrometeroids and the local interstellar cloud (LIC) your starship passes through, to keep your pilots alive long enough (or to have pilot babies) so you are able to stop the star ship successfully when you get to your destination.
In part two, I look at some of the motivations for doing significant development for the 3rd edition.