Never forget: Pong was a clone.
No, seriously. Nolan Bushnell has stated that the inspiration for Pong was the demonstration of Table Tennis for the Magnavox Odyssey, about a month before Pong was first tested in arcades. He saw this demonstration at a tradeshow in which his name was provably in the guestbook. However, to obvuscate this, he proposed the idea to Allan Alcorn, who actually did the programming for it.
Not that Magnavox were any better, to be honest - for context, part of the Odyssey's patent basically patented the ability to interact with player-controlled objects on a television screen (or... yeah, make a video game console, basically), and they deliberately waited a couple of years before suing Atari, Midway, Empire and others for patent infringement (the argument being that they could... make more money from it.) In 1977, it was determined by judge John Grady that the defendants were, in fact, guilty - and Magnavox would continue to sue companies until their patent lapsed, each time being successful or settling because of precedent. This went on until the 90s.
It actually got so bad that Nintendo tried to sue them in 1985, arguing the 1958 game Tennis for Two constituted "prior art" and thus invalidated the Magnavox patent - but they lost, because Magnavox argued that Tennis for Two being played on an oscilloscope instead of a television invalidated this claim.
Man... almost seems like corporations in the gaming space have always been ****ty, huh?