http://ipspotlight.com/2012/06/12/looks-like-tetris-video-game-clones-and-copyright-law/ It seems the courts lumped all falling shape games under the core rules. According to the courts, the rules are Shapes fall from the top THey can be moved and rotated. when a horizontal line is filled, it is removed, and what is above drops down when the stack reaches the top the game is over. Everything else qualifies as expression. OUCH. Yes, this means if you make a falling block game of your own, it can't have only the seven tetrominos. ALL of the following was ruled to be expression 1) field size (yup this means the well width of ten we all know and love, and the visible height of twice well width. But, oh, wait, TGM is official, and uses a size of half that for big mode) 2) piece shapes (yup, use of tetrominos is expression, though i'd call it scènes à faire myself. Nothing else really works out well) 3) rotation behavior (i think maybe if you don't use SRS you might be safe? If they mean 90 degree rotation, well, I'd call that scènes à faire too) 4) ghost piece (at least as an outline, because that's how official games do it, except for TGM. There are other ways to handle it though.) 5) piece colors and appearance (Guideline? better NOT follow it! But they are probably right in this case.) 6) Representation of locked pieces (huh? you have to discolor them or turn them into outlines to not fail this? Oh wait, some official games do that!) 7) piece previews (Oh COME ON! This is so obviously function it's not funny!) Armed with this they can indeed take down everything. Never mind that many of these things are not consistent across legal tetris games.
I've already said so much crap on this topic on HD that I can't be bothered repeating it here. It was a stupid case. Xio were always going to lose, and they didn't have a fucking leg to stand on besides some extremely tenuous one that they'd fabricated from dried peas and string. They'd wholesale ripped off Tetris to make money. They admitted openly to wholesale ripping off of Tetris to make money. If this case didn't go in favour of TTC then there's basically no way to protect video games whatsoever so long as they don't directly steal the name and graphics. Also, you miss out a lot of subtle but important details that come out of the full case report. For starters, having individual aspects of the points you list 1-7 is not infringement. Having ALL (or nearly all) of them is, and you also have to have them all pretty damn loyal to official games when doing so too. Field size exactly 10x20, the seven tetromino pieces no more no less, rotation behaviour that is a solid approximation to SRS, ghost piece, similar colours, locked piece behaviour and piece previews, and the court will deem it to be a Tetris(R) clone. Which, imo, is fair, because if all of those are present and the game doesn't feature any sort of other unique gameplay aspect, then you have made a Tetris(R) clone and most people would probably see it as one. A lot of the aspects were discussed, and the defence of them not being functional features largely fell down because there was no supporting evidence from Xio at having done anything other than just steal the existing stuff. They'd not attempted to design the game from the ground up, looking at Tetris as an inspiration. They'd directly stolen the exact concept with no effort whatsoever to look for potential design improvements or see if things could be done differently. You could perhaps argue that you looked into it and found that exactly a 20x10 field and the seven tetrominos, no more no less, are better than any alternative, but doing that would require some sort of actual design process that Xio not only didn't do, but openly implied that they hadn't even considered doing it.
So does that make King of Stackers infringing, since it copies almost all of the items on that list? Or does the fact that it adds something new save it?
On a direct base of that precedent I'd say that it's not in a great position, but I think from an aspect of being fundamentally different as an experience and having a new take on the existing game it could probably win a separate case. That said, I Am Not A Lawyer.
