To epileptic seizures as of 2007, many video games instruction manuals contain a warning that playing video games may trigger an epileptic seizure ; .4 violence the aforementioned case of death race had set the tone for video games' major source of moral debate: the increasingly detailed graphical depiction of violence. in 1992, midway's mortal kombat went further down that road. designed as a response to capcom's very successful street fighter 2, the game attempted to attract notoriety with excessive, over-the-top content: characters would fly across the screen, throw fireballs, freeze their opponents or instantly teleport themselves, and eventually face a four-armed humanoid and a shape-shifting sorcerer. however, many found these features marginal, due to the exaggerated depiction of blood and gore, with simple jabs causing streams of blood to pour from the opponent's face or body. the one fighting game innovation that caused much of the controversy was the inclusion of gory "fatalities". when an opponent was beaten, instead of dropping to the ground, he or she stood up, stunned and incapable of doing anything. the winner could "finish off" the loser with any move of his choice, and had a few seconds to execute a special command. if done correctly, the character would dismember, incinerate, or behead his victim. unlike death race, more realistic graphics were one of the game's strengths. instead of hand-drawing and animating the characters, the development team filmed real actors, digitized their performance as still photographs, and individually animated them. this made the extreme violence scandalous enough that in 1993 united states senator joseph lieberman arranged a hearing on video games, which he claimed were marketing violence to kids.5 the hearings particularly focused on mortal kombat and the sega cd game night trap 1992 ; , chiefly because these two games featured digitized footage of actors and actresses. the main outcome of these hearings was the creation of the entertainment software rating board esrb ; , a self-regulatory body developed by the video game industry. numerous controversial games followed in the next years. some titles deserving special mention include doom, which popularized the first-person shooter fps ; genre and was used by one of the boys responsible for the 1999 columbine high school shooting, and the grand theft auto series for bringing violence into a realistic contemporary urban setting and letting the player engage law enforcement officials, civilians, and even prostitutes with a wide array of weaponry. sexual content a relatively small and marginal production of erotic video games continued in the wake of custer's revenge, appearing not on video game consoles but rather on personal computers. the most famous of these is sierra's leisure suit larry in the land of the lounge lizards 1987 ; , an adventure game that would span five sequels by 1996 in which the player controlled a middle-aged loser desperately trying to have sex with various women. the visuals were still low-resolution due to the limited graphical power.