Playfield

"PLAYFIELD: This is where the action is."
—Manual for Tetris for NES

The playfield is the grid into which tetrominoes fall, also called the "well" (common in older games) or the "matrix" (especially in more recent Tetris brand games). The playfield is surrounded by a frame called the tetrion, which controls the overall behavior of tetrominoes.

The vast majority of tetromino based game use a playfield 10 cells wide and between 16 and 24 cells tall. Notable exceptions include the following:

• Abandoned Bricks: 9 w
• Gnometris: 11 w until mid-2007; then 14 w
• Tetrinet: 12 w
• Tetris Jr.: 8 w
• Tetris Game Watch: 6 w
• Tetripz: 11 w
• Tetris (NES, Tengen) Cooperative Mode: 12 w
• ТЕТРИС SEMIPRO-68k: 4-32 w (customisable)
• TAP Doubles Mode: 14 w
• Tetris Party Doubles: 20 w
• Full HD Tetris more: 320 w

Columns are conventionally numbered from left to right, and rows from bottom to top.

Vanish zone

Placing blocks in the vanish zone and then revealing them by clearing lines.

The vanish zone is the portion of the playfield above the ceiling. Blocks that enter the vanish zone due to garbage may be truncated or enter a buffer zone depending on the game.

Stack truncation

Games may simply truncate the part of the stack that enters the vanish zone. If the player then clears lines the blocks that were truncated will no longer be present.

This is most often seen in games that use partial lock out (i.e. game over if part of a block locks inside the vanish zone).

Buffer zone

Games may have a buffer zone above the ceiling to store blocks that enter them. In these games, tetrominoes may land and lock partially within the "vanish zone"; they reappear once a line is cleared below them.

For example, the modern Tetris Guideline specifies a visible playfield 10 blocks wide by 20 blocks tall and a buffer zone above the playfield of 20 rows, and the tetrominoes spawn in rows 21 and 22 at the bottom of the buffer zone. This is so that a player with no blocks in the vanish zone can survive 20 rows of garbage sent at once.

Other games may have smaller buffer zones. (Lockjaw is known to use a 24-row playfield.) Most games hide rows 21 and up.