CBS had argued that the show was too similar to its show "Big Brother," but in his decision, U.S. District Judge Gary Feess noted the unpredictable nature of reality television and said the genre does not generally include expressions of ideas that are subject to copyright.
"Until the cameras begin to record, there is no plot, there is no (dialogue), there is no pace or sequence of events, and there are no fixed characters because there is no author," his ruling stated. "There is a setting, which is hardly novel, and some general ideas regarding the structure of the show, but little else."
"'Reality,' it turns out, is hard to copy," Feess wrote.
"We're pleased the Court agreed with ABC's arguments that 'The Glass House' is a very different show and people working in the reality television industry should not be prevented from bringing their skills to a new employer," ABC wrote in a statement.
But the ruling is unlikely to end the fight between the two networks. CBS says it will continue to pursue the case and is seeking additional evidence from ABC and "Glass House" producers.
According to CBS, nearly 30 former "Big Brother" staffers are now working on "Glass House," and some may have violated confidentiality agreements.
"This is only one preliminary step in a long road; we will now aggressively move two steps forward," CBS said in a statement.
The judge issued a tentative ruling last week that allowed "The Glass House" to premiere as scheduled on Monday.
The Associated Press contributed to this report.