On the idea/expression dichotomy and puzzle videogames

Tetris

An interesting case touching upon the fascinating topic of the idea/expression dichotomy has been decided recently by the US District Court for the District of New Jersey. This is Tetris Holding, LLC and Tetris Company, LLC v Xio Interactive, Inc (on which see Wired report here.)

Plaintiffs Tetris Holdings and Tetris Company (respectively, the owner and licensor of copyright and trade dress in well-known 1980s videogame Tetris) brought a lawsuit against defendant Xio Interactive, creator of Mino, a 2009 multiplayer puzzle videogame for iPhone. They claimed, among the other things, federal copyright and trade dress infringements. 

Tetris is a facially simple puzzle game in which the player is tasked with creating complete horizontal lines along the bottom of the playing field by fitting several types of geometric block pieces (called Tetrimino pieces) together. The game becomes more complex and more difficult as one progresses and is left with fewer options to arrange the pieces and less area of the playing field is available. 

Since its first appearance, Tetris Holding has developed numerous versions of Tetris for modern platforms, including iPhone.

According to District Judge Freda Wolfson, the facts of the case were undisputed. 

Background

Mino was created by recent college graduate Desiree Golden, who admittedly used Tetris 
as an inspiration. Actually, Mino was intended to be Golden's version of Tetris and Golden had donwloaded Tetris's iPhone app for the purpose of developing Mino.

Yet defendant Xio, a company formed by Golden, claimed that it had taken inspiration 
from Tetris after diligently researching intellectual property law and in such a way so as not to 
copy any copyright-protected materials. Indeed, the elements copied were said to be 

Mino

non-original expression of Tetris, because they were part of the game itself—the rules, function, and expression essential to the game play—which is not protected. In any case, Xio had also tried to obtain a licence from Tetris Holding, but this was refused.

Shortly after Mino was released, Tetris sent DMCA takedown notices to Apple, which removed Mino from its apps marketplace. However, Xio sent two counter-notifications and Apple informed Tetris Holding that Mino would be reinstated unless Tetris filed a lawsuit. This is what eventually happened.

Tetris Holding claimed that Mino infringed the following original elements of Tetris:

1. Seven Tetrimino playing pieces made up of four equally-sized square joined at their sides;

2. The visual delineation of individual blocks that comprise each Tetrimino piece and the display of their borders;

3. The bright, distinct colors used for each of the Tetrimino pieces;

4. A tall, rectangular playfield (or matrix), 10 blocks wide and 20 blocks tall;

5. The appearance of Tetriminos moving from the top of the playfield to its bottom;

6. The way the Tetrimino pieces appear to move and rotate in the playfield;

7. The small display near the playfield that shows the next playing piece to appear in the playfield;

8. The particular starting orientation of the Tetriminos, both at the top of the screen and as shown in the "next piece" display;

9. The display of a "shadow" piece beneath the Tetriminos as they fall;

10. The color change when the Tetriminos enter lock-down mode;

11. When a horizontal line fills across the playfield with blocks, the line disappears, and the remaining pieces appear to consolidate downward;

12. The appearance of individual blocks automatically filling in the playfield from the bottom to the top when the game is over;

Both Tetris and Mino were iPhone apps

13. The display of "garbage lines" with at least one missing block in random order; and

14. The screen layout in multiplayer versions with the player's matrix appearing most prominently on the screen and the opponents' matrixes appearing smaller than the player's matrix and to the side of the player's matrix.

The judgment

The judge held that it was unquestionable that Mino and Tetris looked alike. However, to resolve the claim of copyright infringement, it was necessary to first determine which elements of Tetris are protected and which are not.

Pursuant to 17 USC §102 and relevant case law, elements of computer programs which may 
be protected by copyright include both the code of the program and its graphical elements. In no case, however, does copyright protection extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained illustrated, or embodied in a work.

The judge acknowledged that the idea/expression dichotomy is simple to state but "difficult to apply, especially in the context of computer programs." [this also because US courts have elaborated many tests to determine what is protectable and what is not]. However, said the judge,

At the end of the day, no matter how one expresses the test, the task is clear: because copyright only protects original expression, I must delineate between the copyrightable expression in Tetris and the unprotected elements of the program, then evaluate whether there is substantial similarity between such expression and Defendant's Mino game. The starting point in this analysis must be to understand the ideas and concepts of Tetris itself.

To this end, two related doctrines must be considered: merger and scènes à faire. Merger exists when an idea and its particular expression become inseparable. The doctrine of scènes à faire applies to expression that is so associated with a particular genre, motif, or idea that one is compelled to use such expression. 

Where expert evidence is gathered
in videogame cases

With these principles in mind, the judge held that:

Xio is correct that one cannot protect some functional aspect of a work by copyright as one would with a patent. 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. Tetris Holding is as entitled to copyright protection for the way in which it chooses to express game rules or game play as one would be to the way in which one chooses to express an idea ... Xio conflates the doctrines of merger and scènes à faire to say that Tetris Holding cannot protect expression inseparable from either game rules or game function ... Xio also relies on a number of opinions discussing video games. In no case, however, did a court find that expression was unprotectible merely because it was related to a game rule or game function. 

Within this framework, the judge then compared the audiovisual aspects of the two games: 

Tetris is a puzzle game where a user manipulates pieces composed of square blocks, each made into a different geometric shape, that fall from the top of the game board to the bottom where the pieces accumulate. The user is given a new piece after the current one reaches the bottom of the available game space. While a piece is falling, the user rotates it in order to fit it in with the accumulated pieces. The object of the puzzle is to fill all spaces along a horizontal line. If that is accomplished, the line is erased, points are earned, and more of the game board is available for play. But if the pieces accumulate and reach the top of the screen, then the game is over. These then are the general, abstract ideas underlying Tetris and cannot be protected by copyright nor can expressive elements that are inseparable from them. [Indeed, in the past few years, many Tetris look-alike versions have been released: just search them on Google]

The parties argued over a number of particular features of both games, which the judge 

Will a 'common user' get upset when he finds out
 that his new videogame is an old game's clone?  

found it appropriate to compare as they would appear to a layman concentrating upon the gross features rather than an examination of minutiae. The conclusion was in the sense that:

Without being told which is which, a 
common user could not decipher between the two games. Any differences between the two are slight and insignificant. If one has to squint to find distinctions only at a granular level, then the works are likely to be substantially similar. Reviewing the videos of the game play bolsters this conclusion as it is apparent that the overall look and feel of the two games is identical. There is such similarity between the visual expression of Tetris and Mino that it is akin to literal copying ... In particular, the style of the pieces is nearly indistinguishable, both in their look and in the manner they move, rotate, fall, and behave. Similar bright colors are used in each program, the pieces are composed of individually delineated bricks, each brick is given an interior border to suggest texture, and shading and gradation of color are used in substantially similar ways to suggest light is being cast onto the pieces. 

This decision is important, in that it further clarifies (also in theoretical terms) the scope of copyright protection for computer programs (in particular videogames), as well as the relationship between the idea/expression dichotomy, merger, and scènes à faire.

As observed by Jack Schecter, the case demonstrates that “the critical fight with clones will be over the appropriate level of abstraction of the game mechanics and gameplay. The Tetris developer’s victory was almost assured once it persuaded the court to identify the underlying game rules and gameplay at a very high level. Having adopted a relatively high-level understanding of the idea of Tetris, the court could readily identify more detailed, granular expressions of that idea that qualified for copyright protection.” 
In any case, what seemed decisive to the actual finding that Xio had infringed Tetris Holding’s copyright were the similarities in the look and feel of the two games (which were held to be tantamount to literal copying), rather than sole reliance on the idea/expression dichotomy.