The Tetris Company has won a copyright dispute against Xio Interactive, the maker of a Tetris-like iPhone game called "Mino." The US District Court of New Jersey ruled that Mino has a "substantial similarity," and therefore infringes on copyright, and represents unfair competition and false endorsement.
Gamasutra reports that Xio Interactive argued it hadn't copied the non-protected elements of the game, since rules and game functionality themselves can't be copyrighted. The court agreed with that argument in principle, but found that Xio had interpreted that too broadly.
"Xio is correct that one cannot protect some functional aspect of a work by copyright as one would with a patent," the filing read. "But this principle does not mean, and cannot mean, that any and all expression related to a game rule or game function is unprotectible. Such an exception to copyright would likely swallow any protection one could possibly have; almost all expressive elements of a game are related in some way to the rules and functions of game play."
Other pending suits over game clones may take note of this precedent, so we might be seeing the ripple effects of this ruling for quite a while.