In a January 1994 Premiere magazine interview about the film The River Wild,
Kevin Bacon commented that he had worked with everybody in Hollywood or someone who's worked with them.
Six Degrees of Kevin Bacon first surfaced at about the same time. On April 7, 1994, a lengthy newsgroup thread headed "Kevin Bacon is the Center of the Universe" appeared.
This logic is used for programming Malevolence: The Sword of Ahkranox to make procedural quest system. If you are still curious about this awesome subject i recommend reading this (Gamasutra) and this (Wiki) articles.