Clones, Variants and the Genre That Grew Around It

Rules are not copyrightable, so a whole family of falling-block games grew up alongside the original.

Within a few years of the original there were dozens of falling-block games, and by now there are thousands. That is not simply piracy; it is how genres form, and it rests on a specific legal distinction.

Rules versus expression

Copyright protects expression — code, artwork, music, text, the specific name. It does not protect an idea, a system or a set of rules. You cannot copyright "shapes fall and complete rows disappear" any more than you can copyright the rules of chess.

What you can protect is your implementation of it, your assets, and your trademark. Which is why a genre could grow: anyone can write a falling-block game, and nobody can call theirs by a protected name or ship somebody else's artwork.

The line has been tested in court, and the outcomes have generally turned on how much of the expression was taken — identical colours, identical proportions, identical presentation — rather than on the mechanic itself.

Where the genre went

Variants explored nearly every direction available:

• Different shapes — five-square pentominoes, mixed sizes, single cells.
• Different clear conditions — matching colours rather than completing

rows, which produced an entire adjacent family of puzzle games.

• Different gravity — pieces falling from multiple directions, or gravity

that reverses.

• Different objectives — dig to the bottom, survive a fixed time, clear a

set pattern, race a rising floor.

• Versus formats — sending garbage to an opponent, which became a genre of

its own.

Most were forgettable. A few became genuinely important games in their own right, and several of the ideas — particularly competitive garbage — fed back into the mainstream of the form.

Where TETERI sits

This game implements the modern conventions the genre converged on, because those rules are good and because players' hands already know them. It uses none of anybody else's code, artwork, music or names; every line was written for it and every sound is generated at runtime.

It is an independent work with no affiliation to any rights holder. The articles here discuss the genre's history and name the companies involved, which is what naming is for — but the game itself owes them nothing but influence, which is the ordinary condition of everything anyone has ever made.

Read next

• Who Invented Tetris?Alexey Pajitnov wrote the original in 1984 at a Soviet research institute, on a computer that could not draw graphics.
• Where the Name "Tetris" Comes FromA Greek numeral prefix welded to the name of a racquet sport, because the author liked both.
• The First Version Ran on a Computer That Could Not DrawThe Elektronika 60 had no graphics mode, so the original pieces were built out of punctuation marks.
• How the Game Escaped the Soviet UnionIt spread by informal copying, reached Hungary, and was picked up by a Western agent before anyone had signed anything.
• Overhangs and Tucks: Placing Pieces Under ThingsA covered space is not lost space. Rotation kicks can reach under an overhang that sliding cannot.
• How Garbage WorksYour clears become rows in your opponent's well, rising from the floor with a single gap in them.