Tetris Guideline

The Tetris guideline is the current specification that The Tetris Company enforces for making all new (2001 and later) Tetris games alike in form. A mode labeled "standard" or just plain "Tetris" will adhere to the Guideline more closely than other modes.

Current rules, learned through observation of the behavior of authentic Tetris games, include:

• Playfield is 10 cells wide and at least 22 cells tall, where the top two may be hidden
• Tetromino colors
  • Cyan I
  • Yellow O
  • Purple T
  • Green S
  • Red Z
  • Blue J
  • Orange L
• At least three next pieces visible
• So-called Random Generator (also called "random bag" or "7 system")
• Tetromino spawn locations
  • The I and O spawn in the middle columns
  • The rest spawn in the left-middle columns
  • The tetrominoes spawn horizontally and with their flat side pointed down.
• Super Rotation System (SRS) specifies tetromino rotation and lockdown behavior
• "Hold piece": The player can press a button to send the falling tetromino to the hold box, and any tetromino that had been in the hold box moves to the top of the screen and begins falling. Hold cannot be used again until after the piece locks down. Games on platforms with extremely limited buttons (such as on iPod) may skip this feature.

The combination of hold piece and Random Generator would appear to allow the player to play forever.

See also

• Tetris Worlds, example of games that follow the Guideline closely

References

• Planet GameCube: Tetris from the Top: An interview with Henk Rogers reveals the existence of the Guideline
• EA Tetris product page, with official names for some Guideline features