The Copycat Conundrum: When Does A Game Become A Clone of Another?

As dialogue surfaces about games being "clones" or "rip-offs" of others in recent memory, Cassidee from Leviathyn.com asks, what makes a game a "clone" of another?

[smashcrashbash]

I personally don't care. All I hope is that PASBR is a good game and Superbot sounds like they are going all out with this game with all types of moves, modes and stages. It definitely is not just cheap knock off as people are trying to make it as. I wish we could have brought the attitudes of gamers back then in the golden age. Despite our differences and disagreement we never behaved the way people do now. I used to argue over who was better Sonic or Mario with my friends all the time but we never took it as personally as gamers do now. Sonic and Mario and every other game could exist at the same time without much conflict. Now it's hate, bias and rage. I mean I don't mind if you have your doubts about it but some of the things being said against it are ridiculous. Some was saying Parappa and Fat Princess don't seem like fighter as opposed to SSB characters. But Mr Game and Watch, Princess Peach, Jigglypuff, Pokemon Trainer and Ness do? Come on.