QUOTE(caffeine @ Jun 13 2012, 08:39 PM)

One-sided tetrominoes used in a playfield that is taller than is wide is de jure functional. A competitor's inability to use these features would make them unable to compete effectively. These combination of features make the game interesting and challenging in the first place. In other words, they are not merely part of the trade dress used to distinguish one product from another. They are part of the functions necessary to establishing the idea (i.e. the gameplay) that consumers enjoy.
This is covered in the legal document (page 31, about halfway down):
QUOTE
Xio defends copying the exact size of the playing field€”20 units high by 10 units wide€”by saying that a rule of the game is to have a board that it higher than it is wide. But having a board higher than it is wide is not the issue; Xio copied a field that was the exact same dimensions as Tetris. Even assuming it is a rule to have a field higher than it is wide, which the Court does not necessarily find, it is not a rule to have the playfield be exactly 20 units by 10 units. Xio was free to program a puzzle game with the playing field designed "in an almost unlimited number of ways" as admitted by Xio€™s expert.
Xio was not limited to those precise dimensions and was free to take the general idea of having a long game board and express it in its own unique way. For example, it could have had a field three times as high as it is wide or 15 units high by 8 units wide, without copying the exact game dimensions and infringing the look and feel of Tetris€™s expression. Thus, I find this to be protectible expression that Xio infringed.
In short, yeah, you're perfectly fine to use a playing field that is taller than it is wide. But you're not fine to use one that is exactly 20x10, or at least not when you're nicking a whole load of other stuff at the same time.
In my opinion the sad thing here is not the ruling itself, but the fact that a ruling that sets such an important precedent like this one has happened in the way that it has, and in a court case that, frankly, was never going to go against TTC.
This dude has shamelessly ripped off Tetris. He is not, like the Cultris or Nullpo devs, attempting to make a cool game that is based around Tetris gameplay for the purposes of filling the currently poorly populated PC Tetris market. He is merely ripping off the concept of official Tetris games, changing as little as he possibly can (basically the name and not using pre-existing graphics, which would be a totally idiotic move not to do anyway), and selling it as a smartphone app with the intention to make some easy money. And he's completely open about his intentions behind the whole thing and his apparently smartass loophole to why he's fine. He's not trying to make a better product to break an existing monopoly, he's just trying to steal someone else's creative work for his own gain.
Basically, he's creating a clone that is in the largest possible way exactly what TTC don't ever want to happen, for fairly obvious reasons. It's also the sort of behaviour that copyright law is obviously in place to attempt to stop. Which means that the court were practically never going to rule in his favour, because setting that sort of precedent basically means that anyone with the resources to clone an existing video game can do so without reprimand, as long as they don't steal the name and exact graphics.
Because this Xio guy has been so much of a dick, it's basically pushed the court into defining what classes as a functional aspect and what classes as trade dress really far towards the "everything is trade dress" side because it's basically the only way to have the copyright law remain defensible against people ripping off games in the way that Mino has done. If there was a shred of creativity about Mino, then there's a chance he could sensibly argue a lot of these features to be necessary for the game design to function, but there isn't. He's not used a 20x10 field for any reasons of gameplay being better; he's used 20x10 because it's what official Tetris games use, and has then tried to defend it as though he did it for the reason of gameplay being better/feasible/playable/whatever, and it hasn't worked.
QUOTE(Integration @ Jun 13 2012, 09:29 PM)

Or the other way around: what must commercial developers fulfil to be protected? Would a combination of memoryless randomizer, different spawning orientions & colors and a unique way to send garbage lines even help you?
They might not make your a** immortal to being sued, but all of those would definitely help you, because they would show that you're making a game that is fundamentally different to Tetris (which could be unintentional and a result of you having a sh** attention to detail, but that's hard to prove). The thing is, if you have a 16x10 field, the game concept would still work, you've created a game that isn't a direct copy, and by the words of the legal stuff said here, you're potentially fine.
What it says in this case is that things like the basic gameplay mechanics (which it defines as being falling blocks that fit together and lines are cleared and stuff) are not covered by copyright and are public domain. So if you want to design a game that uses those gameplay mechanics, you are perfectly entitled to. If you create the game around those mechanics from the ground up then you'll probably come up with something that is similar, but functionally distinct from Tetris, and you're fine. If you can justify any things that are the same (for example the playing field size) with "we explored options but found this one was better for reasons X, Y and Z" then you'd be helping yourself out immensely as basically saying there's only one good solution and it happens to be the same one used in Tetris (this is really hard to prove though and is far from a solid defence).
The copyright law works so that it shouldn't infringe people who want to make games that happen to play similarly to Tetris but were not intended to directly be a Tetris clone. The problem in this particular court case is that Mino
was intended to directly be a Tetris clone, hence losing the ruling and hence setting a precedent that is pretty conservative and has such a large impact on potential fangames.