Multiplayer Tetris: The Definitive Rulebook

[caffeine]

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).

Preface

Knowing 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 rules

T-Spin Mini
In 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 Back
A 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).

Combos
Combo 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 clears
Perfect 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 blocking
You 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 cancelling
With 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 Chance
There 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 Attack
With 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 garbage
After 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 Spin
I 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: 12/16/10

Garbage sent | Type of attack

0 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

Notes

The 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!

[coolmaninsano]

Do(es) B2B bonus line(s) change the garbage hole column?
No?

This is a definite no.

What is the interval between hurry up garbage adds?
Five seconds

5 seconds if playing at a "normal speed", but if one stalls and doesn't drop a piece, for say, 15 seconds, three lines will be added.

[Noogy]

add fumens!!!

[caffeine]

5 seconds if playing at a "normal speed", but if one stalls and doesn't drop a piece, for say, 15 seconds, three lines will be added.

Thanks, but I actually already indicated this in the "General Rules" section.

[iphys]

Unless they've changed things from when I tested a year ago, I don't think TF sends combo garbage on a Perfect Clear either, so I also think it would be doubtful they'd send B2B garbage if you get a B2B Tetris Perfect Clear.

[caffeine]

Unless they've changed things from when I tested a year ago, I don't think TF sends combo garbage on a Perfect Clear either, so I also think it would be doubtful they'd send B2B garbage if you get a B2B Tetris Perfect Clear.

If Perfect Clears didn't stack with combos in the past, then they've changed it since then.

[clincher]

[!--quoteo--][div class=\\\'quotetop\\\']QUOTE[/div][div class=\\\'quotemain\\\'][!--quotec--]What is the chance of hole change upon the new attack?
100%?[/quote]
It's truly random so 90%

[caffeine]

It's truly random so 90%

I've heard this before, but I'm not so convinced. For example, I tested many, many combos earlier today. From what I saw, every discrete combo attack resulted in a 100% hole change.

[crzy242]

I've heard this before, but I'm not so convinced. For example, I tested many, many combos earlier today. From what I saw, every discrete combo attack resulted in a 100% hole change.

i have had many cases where the garbage from the next attack has appeared in the same hole. so yea, i think clinchers right.

[coolmaninsano]

So basically 100% hole change but 11.1111111% for where the next whole is?

EDIT: Is it true that for the middle 8 columns the probability was 11.25% but only 5% for each of the ones on the side? (old system)

[Ravendarksky]

I could be wrong but doesn't a PC send 12 lines?

Also you are stating the rules for E+ TF Multiplayer... not just TF :-)

[crzy242]

I could be wrong but doesn't a PC send 12 lines?

Also you are stating the rules for E+ TF Multiplayer... not just TF :-)

it sends 10 on tf. the +2 you are seeing is a combo bonus

[Rosti_LFC]

i have had many cases where the garbage from the next attack has appeared in the same hole. so yea, i think clinchers right.

I'm also fairly sure that I've received garbage, cleared it, and then gotten more with the hole in the same place.

[caffeine]

I'm also fairly sure that I've received garbage, cleared it, and then gotten more with the hole in the same place.

What I'd like to do is have an opponent just play very slowly (no soft/hard drop, holds when the piece reaches the floor every time), and then I'll do only Doubles, and fill up his stack this way. After a few games, it should become apparent whether or not it's 100%. The only thing is that I may not have time for a couple of weeks to do this test due to the holiday.

I want to also test the B2B Perfect Clear Tetris. What I can do is start off with a regular Tetris and then build up a PC Tetris from there. It may take several trials though (getting A PC is hard, much less a non-opening PC Tetris!).

Also you are stating the rules for E+ TF Multiplayer... not just TF :-)

Yes, I am.

[EnFuego]

I've heard this before, but I'm not so convinced. For example, I tested many, many combos earlier today. From what I saw, every discrete combo attack resulted in a 100% hole change.

I am very certain that I've gotten garbage in the same hole as before with the opponent doing 2 b2b tetris. Could It be 100% different holes for combos and truly random (90%) for other types of garbage?