Modern-day Tetris contains some weird techniques. Some time back they regularized the ruleset of Tetris, using a confidential, yet mostly deduced, system called the Tetris Guideline. Although there are some games that go outside the guideline in some ways, modes that are called standard Tetris, or just plain “Tetris,” must stick to the guideline as a condition of their license agreement.
The Tetris Guideline, by now, has been part of the game for longer than it’s existed without it, but the most popular versions of the game, the Gameboy and NES ports, existed before the Guideline became a thing, so many people who mostly played that version may not be aware of how the game has changed since those days.
Some aspects of the Guideline are a bit controversial, like allowing infinite spin. Others have to do with regularizing how pieces move when rotated, which has some unexpected consequences.
These two short videos contain demonstrations of Tetris piece spinning. Now, I know for a fact that some of these spins are not part of the Tetris Guideline, especially those that involve spinning the “O” piece, the 2×2 square. Apparently a couple versions of Tetris support spinning this piece, even if it doesn’t make sense, and it has the potential to behave in odd ways. It’s interesting to speculate on the exact kind of drugs the spin algorithm is using when they allow pieces to warp into completely enclosed regions.
Here are the videos. Tetris Spins From Satisfying to Cursed (2 1/2 minutes):
And an “All Spins Tutorial” (6 minutes):
While some of the spins are not possible in standard Tetris modes, many of these are. Some games even reward you for pulling them off.
