1UP has just posted an overview of the history of video game lawsuits, and it's especially strong on obscurities, in particular the K.C. Munchkin case: "Atari sued Philips and forced them to stop production of K.C. Munchkin! because Atari had exclusive rights to the home version of Pac-Man, which wasn't due out until 1982. They won on appeal; the court decided that Philips had copied Pac-Man, and that Munchkin's differences only "emphasized" this plagiarism, a ruling that ultimately established how copyright laws would apply to the look and "feel" of software." There's lot more info on Pac vs. Munch via an excellent Patent Arcade article.

Actually, issues regarding plagiarizing game 'look and feel' will come up again at GDC 2006 next March, when Crazy Taxi v. Simpsons Road Rage: Litigating a Gameplay Method Patent will be presented by the lead attorneys for Sega and Radical Games, a fascinating case which "provides a rare insight into the realities facing litigants and the strategies of lawyers in a major patent case involving a core method of gameplay." We'll probably write it up for Gamasutra, too, for the nosy.