The basic game setting was an area known as "The Frontier Sector" where four sentient races (Dralasite, Humans, Vrusk, and Yazirian) had met and formed the United Planetary Federation (UPF). The original homeworlds of the Dralasites, Humans, and Vrusk were never detailed in the setting and it is possible that they no longer existed. A large number of the star systems shown on the map of the Frontier sector in the basic rulebook were unexplored and undetailed, allowing the Gamemaster (called the "referee" in the game) to put whatever they wished there.
Players could take on any number of possible roles in the setting but the default was to act as hired agents of the Pan Galactic corporation in exploring the Frontier and fighting the aggressive incursions of the alien and mysterious worm-like race known as the Sathar. Most published modules for the game followed these themes.
Several new player races appeared in a late addition to the line, Zebulon's Guide to Frontier Space, and include the Humma (which resemble kangaroos), Ifshnit (akin to dwarves), Osakar (lankly, parthenogenic quadrupeds) and Mechanons (intelligent robots).
Characters also each had a Primary Skill Area (PSA—Military, Technological, or Biosocial) which allowed them to buy skills that fell into their PSA at a discount. Skills were rated from 1–6 and usually consisted of a set of subskills that gave a chance for accomplishing a particular action as a base percentage plus a 10% bonus for each skill level the character had in the skill. Weapon skills were based on the character's relevant attribute (Dexterity or Strength) but other skills had a base chance of success independent of the character's attributes. Many of the technological skills were penalized by the complexity of the robot, security system, or computer the character was attempting to manipulate (also rated from 1 to 6).
Characters were usually quite durable in combat—it would take several hits from normal weapons to kill an average character. Medical technology was also advanced—characters could recover quickly from wounds with appropriate medical attention and a dead character could be "frozen" and revived later.
Vehicle and robot rules were included in the "Alpha Dawn" basic set. The "Knight Hawks" rules expansion set included detailed rules for starships. The basic set also included a short "bestiary" of creatures native to the world of Volturnus (the setting for the introductory module included with the basic boxed set), along with rules for creating new creatures.
Character advancement consisted of spending experience points on improving skills and attributes.
A second boxed set called "Knight Hawks" followed shortly. It provided rules for using starships in the setting and also a set of wargame rules for fighting space battles between the UPF and Sathar. Included were counters for starships, two-ten sided dice, a large folding map with open space on one side and on the other a space station and starship (for use with the included adventure), and the adventure SFKH-0: Warriors of White Light.
Adventures printed separately for the game included two more adventures set on Volturnus (SF-1: Volturnus, Planet of Mystery and SF-2: Starspawn of Volturnus continuing the adventure included in the basic set), SF-3: Sundown on Starmist, SF-4: Mission to Alcazzar, SF-5: Bugs in the System and SF-6: Dark Side of the Moon. The last two modules (SF-5 and SF-6) were written by authors from TSR's UK division, and are distinctly different from the others in the series in tone and production style.
Adventures using the Knight Hawks rules included SFKH-1: Dramune Run and a trilogy set "Beyond the Frontier" in which the players learn more about the Sathar and foil their latest plot (SFKH-2: Mutiny on the Eleanor Moraes, SFKH-3: Face of the Enemy, and SFKH-4: The War Machine).
A late addition to the line was "Zebulon's Guide to Frontier Space" which introduced several additional races and radical changes to the game's mechanics. Of the three planned volumes of the Guide, only the first was ever published (in 1985), leaving the game in an uncomfortable, half-overhauled state. Gamers were given little to no practical advice on how to convert their existing characters to the new rules, and TSR never published any further products using the "Zebulon's" concepts.
Current versions of the original game are fanworks. In addition to the Star frontiers Redux and Knight Hawks Vector Rules, a high-quality fan E-zine named "Star Frontiersman" is being published on a regular basis. A multiplayer flight simulator version of Knight Hawks Vector is being developed for Orbiter Space Simulator program, and a virtual tabletop version is also in the works. Play-by-forum post and OpenRPG games are currently being played with new ones starting all the time in the Starfrontiers.org forum.
A version of the setting called "Star Law", which uses the d20 system rules was published as an alternate campaign setting in the d20 Future book. It uses the species names of Vrusk, Dralasite, Sathar, and Yazirian, but is not actually the Star Frontiers setting.