Per the legal case (based on Lucas' acquisition of a 1978 script for Battlestar Galactica)
Appellant Fox argued in its brief that a comparison of the two works discloses at least 34 similarities. For illustrative purposes only, we list 13 of the alleged similarities:
(1) The central conflict of each story is a war between the galaxy's democratic and totalitarian forces.
(2) In Star Wars the young hero's father had been a leader of the democratic forces, and the present leader of the democratic forces is a father figure to the young hero. In Battlestar the young hero's father is a leader of the democratic forces.
(3) The leader of the democratic forces is an older man, displaying great wisdom, and symbolizing goodness and leadership, with a mysterious mystical ability to dominate a leader of the totalitarian forces.
(4) An entire planet, central to the existence of the democratic forces, is destroyed.
(5) The heroine is imprisoned by the totalitarian forces.
(6) A leading character returns to the family home to find it destroyed.
(7) The search by the totalitarians and the liberation attempt by the democratic forces are depicted in alternating sequences between the totalitarian and democratic camps.
(8) There is a romance between the hero's friend (the cynical fighter pilot) and the daughter of one of the leaders of the democratic forces.
(9) A friendly robot, who aids the democratic forces is severely injured (Star Wars) or destroyed (Battlestar) by the totalitarian forces.
(10) There is a scene in a cantina (Star Wars) or casino (Battlestar), in which musical entertainment is offered by bizarre, non-human creatures.
(11) Space vehicles, although futuristic, are made to look used and old, contrary to the stereo-typical sleek, new appearance of space age equipment.
(12) The climax consists of an attack by the democratic fighter pilots on the totalitarian headquarters.
(13) Each work ends with an awards ceremony in honor of the democratic heros.
Ultimately the script was re-worked and the case was dropped with both sides accepting their own legal liability. This gentleman's agreement seems to have been contingent on Lucasfilm's Industrial Light and Magic providing the special effects for the Galactica pilot and series.