Gameplay overview

but norco buy lorazepam cheap diazepam free free ringtones cheap lorazepam adipex online cheap vicodin cheap viagra phentermine online paxil online cheap wellbutrin free free ringtones buy levitra ultram online tramadol online cheap ativan cheap ultracet meridia online free free ringtones paxil online free mtv ringtones online diazepam didrex free nokia ringtones free music ringtones mp3 ringtones free mp3 ringtones samsung ringtones lipitor free sonyericsson ringtones ativan online cialis online vicodin online buy norco cialis online levitra online norco online didrex online funny ringtones hydrocodone online cheap alprazolam hydrocodone free nextel ringtones funny ringtones cialis online sprint ringtones online ativan cheap ativan xanax online free sony ericsson ringtones cheap viagra cheap diazepam fioricet online funny ringtones cheap didrex tracfone ringtones nokia ringtones cheap norco cheap carisoprodol free nokia ringtones ultram online free free ringtones paxil online sagem ringtones paxil online propecia online buy ambien cheap ultram cheap diazepam valium online order viagra free sony ringtones motorola ringtones cheap clonazepam diazepam online online pharmacy online free mp3 ringtones cheap ultracet paxil online cheap diazepam viagra fioricet online online alprazolam valium online nexium online lisinopril online buy clonazepam free ericsson ringtones cheap soma cheap nexium cheap didrex celexa online mp3 ringtones online nexium carisoprodol online cheap meridia cheap ultracet fioricet online free cingular ringtones propecia online soma online funny ringtones alltel ringtones adipex online free nokia ringtones zoloft online cheap sildenafil tramadol online free mono ringtones cyclobenzaprine online soma online cheap cialis albuterol online cialis free funny ringtones nexium online mp3 ringtones cheap paxil cheap clonazepam cheap ultracet soma online free kyocera ringtones fioricet online free jazz ringtones but cyclobenzaprine nokia ringtones buy propecia cheap ativan verizon ringtones cheap fioricet cheap ambien cheap xenical hoodia free tracfone ringtones wellbutrin online order cialis nokia ringtones cheap wellbutrin cheap meridia levitra online free qwest ringtones tramadol online order adipex online meridia cheap propecia real ringtones soma online cheap carisoprodol alprazolam online cheap levitra levitra online free funny ringtones free real ringtones samsung ringtones cheap xanax free motorola ringtones hydrocodone online hgh online cheap valium cheap meridia free cingular ringtones cheap valium order xenical diazepam online cheap phentermine online adipex norco online cool ringtones norco online alprazolam online cyclobenzaprine online buy valium cheap tramadol meridia online wellbutrin online viagra online ultram online propecia online lorazepam online mp3 ringtones cheap hydrocodone ambien online cheap lorazepam online vicodin nokia ringtones nextel ringtones buy ultram order rivotril wellbutrin online xenical carisoprodol online cheap lorazepam clonazepam online free sagem ringtones buy soma alprazolam online nexium online vicodin online vicodin norco online The action of Tetris happens within a machine called a tetrion.

The largest part of the tetrion consists of the playfield measuring ten spaces across by twenty spaces down. It has other parts explained below.

Randomly selected tetrominoes, or shapes consisting of four square blocks, fall from the top of the playfield one at a time. Each tetromino enters the playfield with a given orientation and color depending on its shape. Part of the tetrion, called the piece preview, shows the next pieces that will enter the playfield.

The player can rotate the falling tetromino ninety degrees at a time within the plane of the playfield by pressing the counterclockwise or clockwise rotation buttons, provided the piece has room to rotate. Some versions of the game nudge the tetromino away from the wall or other blocks in order to make room.

The player can shift the falling tetromino sideways one space at a time by pressing the left or right arrow or holding it for quicker movement, provided the piece has room to move. Pieces cannot shift through walls or other blocks.

At the top left, or in some cases the bottom right, of the tetrion is an area called the hold box where a player can store a tetromino for later use. At any time while a tetromino falls, the player can move it to the hold box, and any tetromino held earlier now moves to the top of the playfield. After moving a tetromino to the hold box, the player must then lock the resulting tetromino before holding again (see below).

Each tetromino moves downward slowly by itself. Generally a player can use some method to "drop" the tetromino, or make it move downward faster. Once the tetromino lands on the floor or other blocks, the piece will delay shortly before locking in which time the player can move it. After locking, a player can no longer move the tetromino.

When a tetromino locks and by doing so fills all empty spaces within one or more rows of the playfield, those full rows will clear. Remaining blocks above will move down by as many rows removed.

If the playfield has not filled up with blocks, the next piece enters.