This has been a question that has been bugging me for some time, and still haven't really come up with an answer to it. Gamers are constantly screaming 'RIP-OFF!!!!!' however, they forget that everything is inspired. My question to you is this: At what point are games rip-offs, not inspired?

My theory is that games which have similar controls and visuals to the original, while not improving on the original. For example a Call of Duty 'clone' would be game which feels very similar to Call of Duty, with similar run-and-gun multiplayer, a theme-park style campaign and the same as close to realism as the console can go style graphics. What about you guys? Any theories and ideas?  

Call of Duty clone - are you talking about the followups? =p

All FPS games look the same. Or at least used to, I don't play them, but they looked very similar to each other, which was unappealing.

I think that it all depends on the plot. a CoD game can be wonderful despite being exactly the same as its previous one game-wise, aka, weapons, controls, abilities etc; but the plot and graphics are different - so it's a different game.

If a game is merely trying to cash in on the popularity of a different game, then it is a rip-off. If it actually tries to to be good on its own, then it is inspired.

I think that a game that adds something non-trivial to the experience is inspired. One might also ask what reskins of a game counts as, to which I don't have an answer. That might even depend on how old the game being reskined is. Maybe it's still a great game, but just isn't appealing to modern gamers because it looks bad, so a reskin could be justified and not considered a rip off, though you also wouldn't really call it inspired, either.