In addition, more than a hundred supplemental books provide optional rules and details about different settings and genres (GURPS Martial Arts, for example).

By adapting the various optional rules and systems, GURPS can be run with as much or as little detail as required, and can accommodate virtually any genre, character or style of play.

Attempts were made in Advanced Dungeons and Dragons to allow cross-genre games using Gamma World and Boot Hill rules; however, characters could only be used in a new genre by converting their statistics.

In 1990 GURPS intersected part of the hacker subculture[9] when the company's Austin, Texas, offices were raided by the Secret Service.

The target was the author of GURPS Cyberpunk in relation to E911 Emergency Response system documents stolen from Bell South.

The 1995 supplement GURPS Illuminati University introduced Agatha Heterodyne, the character who would go on to star in the popular comic series Girl Genius in 2001.

Steve Jackson Games released GURPS Fourth Edition at the first day of Gen Con on August 19, 2004.

The changes include modification of the attribute point adjustments, an edited and rationalized skill list, clarification of the differences between abilities from experience and from inborn talent, more detailed language rules, and revised technology levels.

Designed by Sean Punch, the Fourth Edition is sold as two full-color hardcover books as well as in the PDF format.

[12] Role-playing games of the 1970s and 1980s, such as Dungeons & Dragons, generally used random numbers generated by dice rolls to assign statistics to player characters.

)[13] GURPS's emphasis on its generic aspect has proven to be a successful marketing tactic, as many game series have source engines which can be retrofitted to many styles.

[14] Its approach to versatility includes using real world measurements wherever possible ("reality-checking" is an important part of any GURPS book).

GURPS also benefits from the many dozens of worldbooks describing settings or additional rules in all genres including science fiction, fantasy, and historical.

Many game designers began their professional careers as GURPS writers, including C. J. Carella,[15] Robin Laws,[16] S. John Ross,[17] and Steffan O'Sullivan.

For a beginning character in an average power game, the 4th edition suggests 100–150 points to modify attribute stats, select advantages and disadvantages, and purchase levels in skills.

[20] In principle, a Game Master can balance the power of foes to the abilities of the player characters by comparing their relative point values.

A player can select numerous Advantages and Disadvantages to differentiate the character; the system supports both mundane traits (such as above-average or below-average Wealth, Status and Reputation) as well as more exotic special abilities and weaknesses.

This addition to the system greatly increases its flexibility while decreasing the number of specific advantages and disadvantages that must be listed.

GURPS has a wide variety of skills intended to enable it to support any conceivable genre (such as Acrobatics and Vehicle Piloting).

For instance, in a generic medieval fantasy setting, skills for operating a computer or flying a fighter jet would not normally be available.

For instance, a modern boat builder's skills will be of less use if he is stuck on a desert island and forced to work with primitive tools and techniques.

Making statistic and skill checks in GURPS is the reverse of the mechanics of most other RPGs, where the higher the total of the die roll, the better.

Attack modifiers are set by the GM when factoring in things like distance, speed and cover that make a successful strike more difficult.

A common criticism is that characters can achieve a relatively high Active Defense value, drawing out fights considerably.

The only mechanic within the system to address this is the Feint action, which if successful will place the adversary in an unfavorable position, reducing their active defense against that character only, on the subsequent turn.

Like most other RPGs, a loss of hit points indicates physical harm being inflicted upon a character, which can potentially lead to death.

GURPS calculates shock penalties when someone is hit, representing the impact it causes and the rush of pain that interferes with concentration.

Brian Fargo, one of the executive producers of Fallout, stated during an interview that Interplay dropped out of the licensing deal, following fundamental disagreements on the game's content.

[23] GURPS for Dummies (ISBN 0-471-78329-3), a guidebook by Stuart J. Stuple, Bjoern-Erik Hartsfvang, and Adam Griffith, was published in 2006.

Editor Paul Pettengale commented: "Based around a points system and six-sided dice, GURPS succeeds better than most 'generic' games.