Is Tetris copyrightable? [In the US]

[Update: EA is suing Zynga for copying The Sims Social in The Ville.]

Here’s a recent court case on a question that keeps popping up: can a video game be copyrighted? (In the US that is.)

THE TETRIS COMPANY vs. XIO INTERACTIVE, INC.

The Tetris Company sued Xio for copyright infringement for the game Mino. The judge has  ruled against Xio, and hence for the present and future ability of the Tetris Company to sue apparent Tetris clones.

Not being a legal scholar, here are some things I find interesting: Overall, the case doesn’t differ too much in general layout from previous court cases, and it cites generously from previous cases regarding the copyrightability of video games.

The main question concerns the “idea-expression” dichotomy, where by convention an idea is not copyrightable, but the expression of an idea is:

“protection is given only to the expression of the idea—not the idea itself.”

Hence the question really is what parts of Tetris is an idea, and what parts are an expression of that idea. The Tetris company specifically claims that these 14 points are expression:

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;

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 judge does not make a decision for every single claim, but much of the argument concerns whether Mino could have made other decisions than have same size playfield, ghost pieces, and so on. The judge says:

In addition to the design and movement of the playing pieces … I find the following elements are also protected expression and further support a finding of infringement: the dimensions of the playing field, the display of “garbage” lines, the appearance of “ghost” or shadow pieces, the display of the next piece to fall, the change in color of the pieces when they lock with the accumulated pieces, and the appearance of squares automatically filling in the game board when the game is over. None of these elements are part of the idea (or the rules or the functionality) of Tetris, but rather are means of expressing those ideas.

And there you have it. As I read it, this decision seems to pull more game elements into the domain of expression (and hence copyright) than previous decisions did, but I will leave that analysis to others.

(Ars Technica also has a writeup here.)