Wouldn't it be nice if there were actually some kind of precedent set that determined how different a game had to be to be considered a different game legally? Well, it just so happens there is, and it involves Tempest 2000 and Atari! Do you remember there was a Playstation port of Tempest 2000 called "Tempest X"? I always wondered why the name was changed, and other little aspects of the gameplay were altered. years later I managed to chat online with the guy who did the port, and he told me that the changes were made "to reduce the royalty burden".

How so? Well, my original arrangement with Atari was that I was to receive a royalty on any ports of Tempest 2000. "Tempest X" was made exactly enough different that it would be legally considered a different game, cutting me out of any royalties.

Now Tempest X:

- was derived from my source code;
- had exactly the same soundtrack;
- used the same kind of powerup progression as Tempest 2000;
- had a changed name, some extra background effects, and some different web shapes;
- but was close enough to Tempest 2000 that *Tempest 2000 was available as a hidden unlockable by entering a specific word into the highscore table*.

(Furry friends will be amused to hear that that word was "yiff").

Yet now "Atari" claim that TxK is in fact *closer* legally to Tempest 2000 than Tempest X was.