The classic case was a fascinating one
The infamous case between Capcom U.S.A. Inc. v. Data East Corp. did a lot to shape the law around video games and copyright infringment.
Recently, an old video unearthed by Restart Fanzine, which showed a response by a representative of Data East which was submitted to the court in the case, has been circulating the internet.
The video unfortunately is only one part of the full story as it was simply of the representative pointing out the differences between Street Fighter II characters and those from Fighter's History.
The case which was instituted in 1994 by Capcom against Data East was due to the fact that Data East's game, Fighter's History, shared several alleged similarities to Street Fighter II. Capcom sued them for copyright infringement, but would go on to lose as the court ruled that Street Fighter II's concepts were to be considered generic and outside the scope of copyright protection.
This made it possible for a lot of clone games to be made and get away with it even some really blatant ones. However, it also was a way for fighting games to improve as through imitation, there was also innovation. This has ultimately led to better games overall.
Street Fighter has gone on to spawn several sequels and is one of the most infleuntial video games ever made while Fighter's History had two sequels but was discontinued after that which means Capcom had the last laugh.