I think everybody knows what Tetris is by now. If you don’t, then you obviously never owned a game console since the Gameboy. It pretty muck kickstarted the puzzle genre and it spawned countless imitators. The company that owns the trademark, Tetris Holding, is extremely protective. Their latest target was the iPhone game, Mino.

Wired reports that a District judge has ruled that Tetris clone “Mino” was found to be infringing on the copyright of the original puzzle game. How did Mino infringe on that copyright? Let’s take a look at the two games:

Tetris for iPhone

Mino for iPhone

As you can see, the games are pretty much the same. They look the same and obviously play the game, but does that constitute as copyright infringement? As Wired points out, gameplay design has to be patented, so why did the judge rule in Tetris Holding’s favor?

The court had to take apart what it means to be artistic expression protected by copyright and the “mechanical or utilitarian features” of a game that must have a patent. The 14 elements of Tetris that the company claimed Mino copied were deemed to be artistic expression under the court. Here’s what the court had to say:

The “wholesale copying” of Tetris was troubling to the court, which found that the Tetris design, movement, playing field dimensions, display of “garbage lines,” appearance of “ghost” pieces, color changes and automatic fill-in of the game board at the end of the game (all of which were copied by Xio) were aesthetic choices, and were protected, original expressions of an idea. While the idea of a game that required one to rotate figures into a field was not protectible, the design of the component parts was. The court found that the overall look and feel of the games were nearly identical and that any differences between the two were “slight and insignificant.” The court concluded: “There is such similarity between the visual expression of Tetris and Mino that it is akin to literal copying. While there might not have actually been “literal copying” inasmuch as Xio did not copy the source code and exact images from Tetris, Xio does not dispute that it copied almost all of visual look of Tetris.”

So the gist of this case is that Xio could have made any number of puzzle games that played like Tetris and they would have been in the clear. The problem arose because they not only copied the gameplay of Tetris, but the copy was made in a way to intentionally look like Tetris. Pro-tip: If you can prove that people wouldn’t be able to tell your product apart from another, it’s copyright infringement.

Now, don’t get discouraged if you were wanting to make a Tetris clone. There are thousands of puzzle games out there and a lot of them have the same rules. As long as you make the game look different, you can still use the same rules of Tetris. You can even change it up and add your own rules. Here’s a few great examples of games that took Tetris and made it better:

It’s easy to make your own puzzle game and not copy Tetris. All these games copied and made their own tweaks to the Tetris design for you. Now, I’m not condoning that you blatantly copy any of these games, but I am saying that it’s easy to create your own unique puzzle game while following the rules of the genre.