DISCLAIMER: I’m not perfect! If you see any mistakes, please let me know! However, please do not claim something is incorrect unless you have tested it firsthand and are 100% sure of it (it’s very easy to mix up how many lines each attack sends in real games where not only do you have multiple attacks going on at once, but they are also subject to cancelling).PrefaceKnowing the rules can really make an impact on how we play the game. Even the small details can make a huge difference on game balance and what kind of strategy we should follow (e.g. how garbage blocking can affect combos), and boy has Tetris become ever so complicated over these past few years! So, when I tried looking up these rules online, I was surprised to find out just how difficult they are to dig up. My goal is to lay these rules out in plain sight, so multiplayer Tetris strategy is no longer so cryptic.
General rulesT-Spin MiniIn Tetris Friends, a T-Spin Mini must fulfill a set of conditions within a normal T-Spin:
- Same rules as a regular T-Spin apply (last event before locking was a rotation, and not a movement or row descension, and three of the four corner cells surrounding the T's middle are filled)
- Must clear a single line or no line at all.
- The T's “middle finger” mino is sandwiched between an empty cell and a filled cell within the 4-point T-Spin.
- If you use a kick which pulls the tetromino’s center mino downward two rows (the T-Spin Triple kick), then the T-Spin will not result in a mini, unless the kick was succeeded by a new movement and/or kick and/or a row descension (in which case the conditions reset).
In Tetris Online (Japan), a T-Spin Mini must fulfill a different set of conditions within a normal T-Spin:
- Same rules as a regular T-Spin apply (last event before locking was a rotation, and not a movement or row descension, and three of the four corner cells surrounding the T's middle are filled)
- Must clear a single line, and only a single line clear.
- The T's last rotation used a kick.
- The T is in a spot where it cannot rotate without using a kick.
Back 2 BackA B2B chain will begin with a Tetris or a T-Spin that clears a line (including T-Spin Minis). All Tetrises and T-Spins (that clear lines) excuted within the B2B chain will yield a B2B bonus. Clearing a line with something other than a T-Spin or Tetris will end the B2B chain (i.e. a Single, Double, or Triple).
CombosCombo attacks "stack" on top of other attacks. So, in Tetris Friends, if you clear a Combo 2 as a Double, you will send a line for the Double and another line concurrently for the Combo 2 bonus.
Perfect clearsPerfect clears do not "stack" with other attacks, except for combos. In other words, a Perfect Clear executed by clearing a Tetris will not send four lines in addition to the original ten line Perfect Clear attack. (Note: there are some games where Perfect Clears stack with other attacks.)
Garbage blockingYou will not receive pending incoming garbage lines until locking a tetromino that does not clear a line (i.e. you won't receive a garbage line so long as you clear a line with your current tetromino).
Garbage cancellingWith exception to garbage blocking, you will not receive pending incoming garbage until locking your current tetromino. If, with that locked piece, you yourself send an attack, then this will reduce your incoming garbage by how many garbage lines you would’ve sent. If you would’ve sent more than your opponent, he or she will receive the difference.
Hole Change ChanceThere are 10 columns, and each row of garbage will contain a hole on one of these 10 columns. In normal randomness, the hole will "change" to a new column 9/10ths of the time, which is a 90% hole change chance. Some games alter this to either make garbage easier or more difficult. For example, a 100% hole change chance means that the garbage will never line up. That means you will never be able to clear more than one garbage row at a time. Whereas, when holes line up, you can clear multiple garbage rows with a single piece (as is possible in games that have less than 100% hole change).
Change on AttackWith change on attack garbage, individual attacks are sent in groups of lined-up garbage. For example, a Tetris will send four rows of lined-up garbage. The next attack may start on a different column. In games without change on attack, garbage is distributed randomly, regardless of what type of attack you make (based on the hole change percentage).
Hurry up garbageAfter enough time passes, both players will receive a solid, "unclearable" row of garbage in regular intervals. Normal, "attacking," garbage spawns on top of these solid rows. Although it will wait until your tetromino locks, hurry up garbage is not subject to garbage blocking.
All SpinI don’t actually know the detection rules for All Spins and All Spin Minis, found in Amagami Tetris and Tetris Party Deluxe. I’ll fill this in later when someone enlightens me.
Tetris Friends; E+ mode; Last updated: 12/16/10Garbage sent | Type of attack0 Single
1 Double
2 Triple
4 Tetris
2 T-Spin Single
4 T-Spin Double
6 T-Spin Triple
0 T-Spin Mini Single
10 Perfect Clear
5 B2B Tetris
3 B2B T-Spin Single
5 B2B T-Spin Double
7 B2B T-Spin Triple
0 B2B T-Spin Mini Single
10? B2B Perfect Clear Tetris
0 Combo 1
1 Combo 2
1 Combo 3
1 Combo 4
2 Combo 5
2 Combo 6
3 Combo 7
3 Combo 8
4 Combo 9
4 Combo 10
4 Combo 11
5 Combo 12 or more
Note: In this game, non-"E+" modes' Combo 5 and 6 send 3 lines each and Combo 7 and 8 sends 4 lines each.What is the chance of a garbage hole change?
100%
Is there change on attack garbage?
Yes
Is there garbage canceling?
Yes
Is there garbage blocking?
Yes
How long until hurry up garbage takes effect?
Two minutes and in five second intervals after that
Is there an All Spin Bonus?
No
NotesThe rules with question marks are my best guesses, but I am not 100% certain on them. Also, I’d like to expand this thread to other games. If you'd like to help, just copy and paste the above list and fill it out for the new game. I’ll be happy to list it here and credit you. Also, if you know of any other conditions I should list, please let me know. Although, I’d like to keep this post restricted to popular licensed online games from the “Tetris DS era” onward so there isn’t a hundred useless conditions that are the same for every game anyway.
Thank you deepcube and clincher for helping me test this stuff out! Also, thank you to Kitaru, meow, and DarthDuck!