[derefr]

That doesn't sound right. Physical, non-video-game instantiations of tetrominoes exist, and Tetris Holdings, LLC presumably doesn't hold trademark over those.

It'd be like trying to trademark a d20. Sure, one with symbols/numbers on it, as viewed from a certain angle, stylized a certain way, might be trademarkable as a mark (i.e. a logo.) But isocahedrons generally? They're mathematical objects.

Which means that, presumably, you could make a Tetris clone as a board game (which would work a bit like Connect Four, I guess) without any exposure.

[bitwize]

Trademarks are funny in that they are confined to certain markets. If you do not compete in a trademark owner's business, you can use the mark. You see this in the wild: the word Namco, for instance, is trademarked to a Japanese video game company and an American swimming pool company. The word Shazam can refer to a superhero owned by Warner Bros., an app owned by Apple, or a financial services company called Shazam Inc. with a separate trademark for all three. And there's some interesting trademark history behind the name "Apple" itself!

So yes, while the tetrominos being a Tetris Company trademark precludes their unlicensed use in video games, they can be used in other contexts -- a tetromino pattern on pyjamas or wallpaper, for instance.

However, I would be wary about attempting to use them in a board game, as I seem to recall at least one licensed Tetris board game in the wild. Consult an attorney before proceeding. :)

[defertoreptar]

> So yes, while the tetrominos being a Tetris Company trademark precludes their unlicensed use in video games

Tetrominoes are not a Tetris Company trademark. They have, however, trademarked the word "tetrimino."