At the start of a game, the server will send the client a "newgame" message, which will look something like this:

<pre><code>newgame 0 1 2 1 1 1 18 33333333333333555555555555552222222222222224444444444444466666666666666777777777777771111111111111111111111111111111111111111111111112222222222222222222234444444444444566666666666666678888889999999999 0 1ÿ</code></pre>

Tetrifast servers will substitute seven asterisks <code>*******</code> for the <code>newgame</code>

This string, which represents the game rules, breaks down as follows:

<pre><code>newgame <starting height> <starting level> <lines per level> <level increment> <lines per special> <specials added> <special capacity> <block frequencies> <special frequencies> <average levels> <classic rules></code></pre>

or

<pre><code>******* <starting height> <starting level> <lines per level> <level increment> <lines per special> <specials added> <special capacity> <block frequencies> <special frequencies> <average levels> <classic rules></code></pre>

|_{width:140px}. argument |_{width:72px}. type |_{width:45px}. values |_. meaning |
| <code>starting height</code> | integer | ≥<code>0</code> | the number of [[garbage lines|generating garbage lines]] that should be present at the bottom of each player's field when the game starts |
| <code>starting level</code> | integer | ≥<code>1</code> | the level at which all players begin the game |
| <code>lines per level</code> | integer | ≥<code>1</code> | the number of lines a player must clear to advance to the next level |
| <code>level increment</code> | integer | ≥<code>0</code> | the number of levels a player advances when he or she completes the requisite number of lines |
| <code>lines per special</code> | integer | ≥<code>1</code> | the number of lines a player must clear before [[specials are added|adding specials to the field]] to his or her field |
| <code>specials added</code> | integer | ≥<code>0</code> | the number of specials added to a player's board when he or she completes the requisite number of lines |
| <code>special capacity</code> | integer | ≥<code>0</code> | the number of specials a player can hold in his or her queue at a given time. specials collected beyond this number are discarded |
| <code>block frequencies</code> | string of 100 integers | <code>1</code> - <code>7</code> | the frequency of occurrence (each number being 1%) of each of the different [[block types]] |
| <code>special frequencies</code> | string of 100 integers | <code>1</code> - <code>9</code> | the frequency of occurrence of each of the different [[special blocks]] |
| <code>average levels</code> | boolean | <code>1</code> or <code>0</code> | if <code>1</code>, the client should display the average levels of all players in the game (<code>0</code> just means the value is hidden) |
| <code>classic mode</code> | boolean | <code>1</code> or <code>0</code> | if <code>1</code>, [[classic-style adds]] are enabled |