Superworld

Superworld is a superhero-themed role-playing game published by Chaosium in 1983 that uses the generic "Basic Role-Playing" rules system. The game began as just one part of the "Worlds of Wonder" product before being published as a stand-alone game. In competition against other well-established and popular superhero games, "Superworld" never found an audience, and was discontinued after only three supplements were published for it.
Game system.
"Superworld" uses Chaosium's "Basic Role-Playing" system, with the addition of rules for super-powers.
Components.
The game box contains 
Editions printed in 1984 and later also contain a 4-page booklet of errata.
Character generation.
Characters are generated by rolling two six-sided dice and adding 6, to produce scores for Strength, Constitution, Size, Intelligence, Power, Dexterity, and Appearance. The sum of these characteristics gives a total of Hero Points used to buy super powers. Hero Points can also be used to buy skills or increase characteristics. It is possible to earn more Hero Points by choosing a Disability such as Public Identity, Vulnerability to a Substance, or Psychological Problems. More Hero Points are awarded for experience at the end of each game session.
The super powers system imitates the system used in Hero Games' "Champions" superhero game, where powers are described by their effects, not by their causes. For example, the player does not buy "Laser Vision" to cause an energy blast, but instead buys the effect "Energy Blast", which specifies that it caused by a laser beam emitted by the hero's eyes. Each effect can be modified by Advantages (less energy expenditure, for example) or Disadvantages (reduced number of uses, for example) which increase or reduce the cost of a power.
Skills resolution.
As with all games using the "Basic Role-Playing" rules, skill tests and combat are resolved by rolling percentile dice against skills. Rolls that are much lower than needed can result in increased effect, while high rolls can cause critical failures. Combat rules have many options and take into account three types of energy for damage: Kinetic, Electric, and Radiation.
Publication history.
In 1982, Chaosium published "World of Wonders" to demonstrate the flexibility of its generic "Basic Role-Playing System"; the game included three separate settings with the idea that player characters could be moved from setting to setting using the same rules system: 
The following year, "Superworld" was published as a stand-alone boxed set designed by Steve Perrin, with interor illustrations by Chris Marrinan, Markus Harrison, and cover art by Michael Dooney.
Three supplements followed:
Up against well-established rival superhero games "Villains & Vigilantes" (Fantasy Games Unlimited) and "Champions" (Hero Games), "Superworld" was not able to establish a strong player base, and no further supplements were released by Chaosium.
Reception.
Jon Sutherland reviewed "Superworld" for "White Dwarf" #51, giving it an overall rating of 7 out of 10, and stated that "This represents an intelligent attempt to provide a playable format for a difficult topic to simulate. The only rules that I have ever seen with anything like this in scope was the "Golden Heroes" FRP which may soon be available in a modified form from "GW"."
Steve Marsh reviewed "Superworld" in "Ares Magazine" #17 and commented that "The game is anything but chaotic, but should create change in any gaming group that sees it. It is well done, and worth the price."
Crede Lambard reviewed "Superworld" in "Space Gamer" No. 70. Lambard commented that ""Superworld" is very good. I doubt that it will ever supplant "Champions", but it certainly supplements it . . . especially now that both Hero Games and Chaosium are putting out adventures with stats for both games."
"Wild Cards".
The "Wild Cards" series of science fiction books came from a "Superworld" campaign gamemastered by George R. R. Martin, and played in by other science fiction writers.