Doom (1993 video game)
Because id planned to self-publish the game, as the game neared completion they had to set up the systems to sell the game. Jay Wilbur, who had been brought on as CEO and sole member of the business team, planned the marketing and distribution of "Doom". He felt that the mainstream press was uninterested in the game, and as id would make the most money off of copies they sold directly to customers—up to 85 percent of the planned US$40 price—he decided to leverage the shareware market as much as possible, buying only a single ad in any gaming magazine. Instead, he reached out directly to software retailers, offering them copies of the first "Doom" episode for free, allowing them to charge any price for it, in order to spur customer interest in buying the full game directly from id.
First-person shooter
"Doom" has been considered the most important first-person shooter ever made. It was highly influential not only on subsequent shooter games but on video gaming in general, and has been available on almost every video gaming system since. Multiplayer gaming, which is now integral to the first-person shooter genre, was first achieved successfully on a large scale with "Doom". While its combination of gory violence, dark humor and hellish imagery garnered acclaim from critics, these attributes also generated criticism from religious groups, with other commentators labelling the game a "murder simulator." There was further controversy when it emerged that the perpetrators of the Columbine High School massacre were fans of the game; the families of several victims later unsuccessfully attempted to sue numerous video game companies - among them id Software - which the families claimed inspired the massacre. In 1994, Raven Software released "Heretic", which used a modified version of the "Doom" engine that allowed for vertical aiming, an inventory system to store and select items, and gibs.