Egbert was born in Dayton, Ohio and grew up in Huber Heights, a Dayton suburb, attending Wayne High School. He was a child prodigy, and entered Michigan State University at age 16, where he majored in computer science. Personal problems cited in the reports of his suicide attempt and disappearance include depression, loneliness, parental pressure, drug addiction, and (according to detective William Dear) difficulty in coming to terms with his homosexuality.
On August 15, 1979, after writing a suicide note, Egbert left his dormitory room at Case Hall and entered the university's steam tunnels. He consumed some methaqualone, intending to commit suicide, but the attempt proved unsuccessful. After waking up the next day, he went into hiding at a friend's house.
A police search for Egbert began. The story was followed widely in the news media after Michael Stuart, a journalist for the university's newspaper, The State News, published details. Egbert's parents hired a private investigator, William Dear, to find their son. Knowing little about fantasy role-playing games, Dear theorized that Egbert's disappearance was related to his involvement with the Dungeons & Dragons game, a possibility further promoted in subsequent news media. Students were reported to play live-action sessions of the game in the steam tunnels below the school, and it was speculated that Egbert was injured or otherwise disappeared during such a session.
The search for Egbert continued unsuccessfully for several weeks, during which Egbert moved to two other houses in East Lansing before finally leaving the city via bus for New Orleans.
Egbert made a second suicide attempt in New Orleans by consuming a cyanide compound, which also failed. He then moved to Morgan City, Louisiana and was employed as an oil field laborer. After four days on the job, Egbert called Dear and revealed his location. Dear traveled to Louisiana (others reported Texas) and recovered Egbert. Upon their meeting, Egbert asked the investigator to conceal the truth of his story. Dear agreed and released Egbert to the custody of his uncle, Dr. Marvin Gross, on September 13, 1979.
Egbert died of a self-inflicted gunshot wound on August 16, 1980. In 1984, Dear revealed Egbert's story in The Dungeon Master.
The idea of Dungeons & Dragons players acting out real-life sessions in dangerous locations like the steam tunnels and losing touch with reality became ingrained into the cultural consciousness, inspiring movies such as Mazes and Monsters. The perceived link between Egbert's disappearance and Dungeons & Dragons was one of several controversies linked to the game during the 1980s.
In 1988, during an investigation into his stepfather's murder, Christopher Wayne Pritchard told the police that he and his friends had mapped the steam tunnels of North Carolina State University for the purposes of incorporating them into their Dungeons & Dragons role-playing.In 1981, Rona Jaffe fictionalized the case in her novel Mazes and Monsters. The book was adapted for the made-for-television movie Mazes and Monsters in 1982. In the novel, a group of college friends playing the role-playing game 'Mazes and Monsters' use an abandoned mine near their college campus for a live-action version of the game. One of the students (played by Tom Hanks in the movie) suffers a psychotic breakdown while playing the game.
In 1983, an episode of The Greatest American Hero titled "Witches and Warlocks" depicted live-action role playing at a fictional university's steam plant.
In 1984, Neal Stephenson wrote the university satire The Big U, in which several live-action role playing gamers head into their university's sewers to play a game called "Sewers and Serpents".