Difference between revisions of "Arika Rotation System"

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'''Arika Rotation System''' (also known as '''ARS''') is a set of gameplay mechanics, used in [[TGM series|the ''Tetris: The Grand Master'' series]], ''[[Tetris with Cardcaptor Sakura Eternal Heart]]'', and many [[fan games]]. It is derived from [[Sega rotation|Sega's rotation system]].
 
'''Arika Rotation System''' (also known as '''ARS''') is a set of gameplay mechanics, used in [[TGM series|the ''Tetris: The Grand Master'' series]], ''[[Tetris with Cardcaptor Sakura Eternal Heart]]'', and many [[fan games]]. It is derived from [[Sega rotation|Sega's rotation system]].
  
Games using Arika Rotation System generally use [[IRS#IRS|IRS]], fast [[DAS]], [[lock delay]], and sonic [[drop]]. Tetrominoes usually appear in the 20th and 19th row, unlike guideline games which appear in the 22nd and 21st rows. The "ARS" and "ARS2" modes of ''[[Tetris The Grand Master Ace]]'' use a hybrid of ''TGM'' rules and [[Tetris Guideline|Guideline]] rules.  
+
Games using Arika Rotation System generally use [[IRS#IRS|IRS]], fast [[DAS]], [[lock delay]], and sonic [[drop]]. Pieces usually appear in the 20th and 19th row, unlike guideline games which appear in the 22nd and 21st rows. The "ARS" and "ARS2" modes of ''[[Tetris The Grand Master Ace]]'' use a hybrid of ''TGM'' rules and [[Tetris Guideline|Guideline]] rules.  
  
 
''Tetris with Cardcaptor Sakura Eternal Heart'' uses a modified version of ARS that does not have Mihara's conspiracy.
 
''Tetris with Cardcaptor Sakura Eternal Heart'' uses a modified version of ARS that does not have Mihara's conspiracy.
  
 
== Basic rotation ==
 
== Basic rotation ==
The basic rotations inherits their properties from Sega rotation, which was used in older Japanese ''Tetris'' games since 1988. Some defining characteristics include:
+
The basic rotation states of pieces is identical to Sega rotation, which was used in older Japanese ''Tetris'' games since 1988.
* Having 2 (as opposed to 4) rotation states for S, Z, and I tetrominoes.
 
* Keeping tetrominoes at an even level while rotating to always allow rotation when the tetromino is on a flat surface (except for the I tetromino - see exceptions below).
 
* Pointing the initial state of the T, L, and J tetrominoes downward.
 
[[Image:Tgm basic ars description.png|none|frame|TGM's basic rotations.]]
 
  
== Wall kicks ==
+
Some defining characteristics include:
Up to 3 locations are tried, in this order, before rotation will fail:
+
* All pieces except for the I-piece have its rotation states aligned towards the bottom of the piece's bounding box. This allows a piece to rotate after landing on a flat surface, without requiring floor kicks.
 +
* I, S, and Z-pieces only have two states, and rotating in either direction simply toggles their state.
 +
* Unlike Sega rotation, L, J, and T pieces can be rotated both clockwise, and counterclockwise.
 +
* The initial state of the L, J, and T-pieces have their longest flat side facing up.
 +
[[Image:Tgm basic ars description.png|none|frame|Arika Rotation System's basic rotations.]]
  
 +
== Kicks ==
 +
When basic rotation fails due to the piece colliding with the edges of the [[playfield]] or the stack, two kicks are tested.
 +
 +
The process is as follows:
 
# Basic rotation
 
# Basic rotation
# 1 space right of basic rotation
+
# Kick 1 space to the right of basic rotation
# 1 space left of basic rotation
+
# Kick 1 space to the left of basic rotation
 +
 
 +
In addition to these rules, there are some extra exceptions where certain kicks are not allowed.
 +
* The I-piece will never kick.
 +
* L, J, and T-pieces, from their 3-wide orientations, will not kick off their center column.
 +
 
 +
=== Center column rule ===
 +
The center column rule prevents many unusual kicks which would otherwise be possible without the rule. Another side effect of the rule is that some rotations are not reversible, unlike with [[SRS]].
  
In addition to these rules, there are some extra exceptions where certain wall kicks are not allowed:
+
L, J, and T-pieces use a 3x3 bounding box to hold the piece information, when referring to the center column, it means the center column of the bounding box. If any of these three pieces are rotated, an algorithm checks if the piece collides with the stack or playfield edges.
  
* The I tetromino will never kick.
+
The algorithm for checking colliding blocks searches in the following pattern:
* L, J, and T tetrominoes, from their 3-wide orientations, will not kick off their center column. In the situations illustrated below if the [[Image:XTet.png|X]] marked block is occupied.
+
{|
 +
|<playfield>
 +
123
 +
456
 +
789
 +
</playfield>
 +
|}
 +
If the first block found in the search is a center column block (cells 2, 5, or 8), the rotation will fail. However, if the first block found isn't in the center column, and a kick is possible, then a kick is applied.
  
 +
In the situations illustrated below if the [[Image:XTet.png|X]] block is occupied.
 
{|
 
{|
|width="200pt"|<playfield>
+
|<playfield>
 
.......X..
 
.......X..
 
.LLL..LLL.
 
.LLL..LLL.
 
.LX...L...
 
.LX...L...
 
</playfield>
 
</playfield>
|width="200pt"|<playfield>
+
|<playfield>
 
..X.......
 
..X.......
 
...L...XL.
 
...L...XL.
Line 54: Line 73:
 
|}
 
|}
  
However, there are very similar situations where additional off-center blocks will enable a wall kick, due to a bug in the way blocks that block a rotation are detected. In the situations illustrated below, the upper [[Image:XTet.png|X]] blocks are off-center and enable the kick even in the presence of [[Image:XTet.png|X]] blocks in the center column.
+
However, there are very similar situations where additional off-center blocks will enable a wall kick. In the situations illustrated below, the upper occupied blocks are off-center and enable the kick even in the presence of occupied blocks in the center column.
  
 
Clockwise rotation will successfully kick:
 
Clockwise rotation will successfully kick:
 
{|
 
{|
|width="200pt"|<playfield>
+
|<playfield>
 
.X......X.
 
.X......X.
 
.LLL..JX..
 
.LLL..JX..
Line 67: Line 86:
 
Counter-clockwise rotation will successfully kick:
 
Counter-clockwise rotation will successfully kick:
 
{|
 
{|
|width="200pt"|<playfield>
+
|<playfield>
 
...X..X...
 
...X..X...
 
.JJJ...XL.
 
.JJJ...XL.
Line 74: Line 93:
 
|}
 
|}
  
Those situations successfully kick, because the algorithm for checking blocking blocks searches in the following pattern:
+
== Kicks added in Tetris The Grand Master 3 Terror-Instinct ==
{|
+
A number of kicks were added to ''[[Tetris The Grand Master 3 Terror-Instinct]]'' that eliminate common traps, and allow faster play.
|width="200pt"|<playfield>
 
123
 
456
 
789
 
</playfield>
 
|}
 
If the first block found in the search is a center column block, the rotation is blocked. But if the first block found isn't in the center column, and a kick is possible, then a kick is applied.
 
  
== Kicks added in ''[[Tetris The Grand Master 3 Terror-Instinct]]'' ==
 
 
=== I-piece wall kicks ===
 
=== I-piece wall kicks ===
In ''Terror-Instinct'', the I-pieces can kick walls and the stack. There are two different wall kicks.
+
In ''Terror-Instinct'', the I-piece can kick walls and the stack. There are two different wall kicks.
 
{|
 
{|
 
|width="150"|<playfield>
 
|width="150"|<playfield>
Line 184: Line 195:
 
|}
 
|}
  
=== I tetromino's floor kicks ===
+
=== I-piece floor kicks ===
The I tetromino can kick the floor, but it can be performed only once and cannot kick the floor in mid-air.
+
The I-piece can kick the floor, but it can be performed only once and cannot kick the floor in mid-air.
  
 
{|
 
{|
Line 270: Line 281:
 
|}
 
|}
  
=== T tetromino's floor kicks ===
+
=== T-piece floor kicks ===
The T tetromino can escape from a hollow, up to two times.
+
The T-piece can escape from a hollow, up to two times.
  
 
{|
 
{|
Line 297: Line 308:
 
|}
 
|}
  
Rotating a T or I tetromino after it has floor kicked will permanently set the lock delay for that tetromino to zero. This is actually what prevents the second I floorkick. After the second rotation is processed, movement gets processed, allowing a shift of one cell left or right if it's done fast enough. Gravity is then applied.  If the I tetromino is not in contact with an occupied cell below after processing gravity, any attempt to floorkick will fail, as explained above. If contact does exist, the tetromino will instantly lock down, preventing rotation from being processed at all.
+
Rotating a T or I-piece after it has floor kicked will permanently set the lock delay for that piece to zero. This is actually what prevents the second I floorkick. After the second rotation is processed, movement gets processed, allowing a shift of one cell left or right if it's done fast enough. Gravity is then applied.  If the I-piece is not in contact with an occupied cell below after processing gravity, any attempt to floorkick will fail, as explained above. If contact does exist, the piece will instantly lock down, preventing rotation from being processed at all.
  
The T tetromino has no such restriction, so it IS possible to make it floor kick twice, but it will lock after the second one because there is no way to process rotation again before it locks.
+
The T-piece has no such restriction, so it ''is'' possible to make it floor kick twice, but it will lock after the second one because there is no way to process rotation again before it locks.
  
 
== Right side bias ==
 
== Right side bias ==
  
In ''TGM'''s rotation system, the Tetrominoes rotate on only one axis resulting in asymmetrical rotations. In this example, the I piece can't rotate on the left side of the stack;
+
In ''TGM'''s rotation system, the pieces rotate on only one axis resulting in asymmetrical rotations. In this example, the I-piece can't rotate on the left side of the stack;
  
 
<playfield>
 
<playfield>
Line 322: Line 333:
 
I piece's rotation axis
 
I piece's rotation axis
  
This case does not apply to the T tetromino, as it rotates on its center;
+
For this reason it is recommended to build a well on the right side of the playfield, rather than the left. This bias is seen in other games, such as [[Tetris (NES, Nintendo)|NES Tetris]].
 
 
<playfield>
 
.I.
 
ICI
 
</playfield>
 
T rotation axis
 
  
 
== Mihara's conspiracy ==
 
== Mihara's conspiracy ==
 
 
Due to the right side bias with wall kicks, doing this move with a J when there is an empty hole right of the block that the J is caught on will lead to a hole.
 
Due to the right side bias with wall kicks, doing this move with a J when there is an empty hole right of the block that the J is caught on will lead to a hole.
  
Line 443: Line 447:
 
Kicks to here
 
Kicks to here
 
|}
 
|}
 +
 +
This can be taken advantage of to rotate the J-piece over obstacles during 20G.
 +
{|
 +
|<playfield>
 +
..........
 +
....JJ....
 +
....J.....
 +
GGG.J.G...
 +
GGG.GGG...
 +
GGGGGGGGG.
 +
GGGGGGGGG.
 +
</playfield>
 +
IRS counterclockwise
 +
|<playfield>
 +
..........
 +
.....JJ...
 +
.....J....
 +
GGG..JG...
 +
GGG.GGG...
 +
GGGGGGGGG.
 +
GGGGGGGGG.
 +
</playfield>
 +
Move right
 +
|<playfield>
 +
..........
 +
..........
 +
.....JJJ..
 +
GGG...GJ..
 +
GGG.GGG...
 +
GGGGGGGGG.
 +
GGGGGGGGG.
 +
</playfield>
 +
Rotate clockwise
 +
|<playfield>
 +
..........
 +
..........
 +
..........
 +
GGG...G...
 +
GGG.GGGJJJ
 +
GGGGGGGGGJ
 +
GGGGGGGGG.
 +
</playfield>
 +
Place piece
 +
|}
 +
 +
In ''Tetris with Cardcaptor Sakura Eternal Heart'', Mihara's conspiracy was fixed, and instead, pieces will only kick inward.
  
 
== ACE-ARS and ARS2 ==
 
== ACE-ARS and ARS2 ==

Latest revision as of 19:54, 13 January 2020

Arika Rotation System (also known as ARS) is a set of gameplay mechanics, used in the Tetris: The Grand Master series, Tetris with Cardcaptor Sakura Eternal Heart, and many fan games. It is derived from Sega's rotation system.

Games using Arika Rotation System generally use IRS, fast DAS, lock delay, and sonic drop. Pieces usually appear in the 20th and 19th row, unlike guideline games which appear in the 22nd and 21st rows. The "ARS" and "ARS2" modes of Tetris The Grand Master Ace use a hybrid of TGM rules and Guideline rules.

Tetris with Cardcaptor Sakura Eternal Heart uses a modified version of ARS that does not have Mihara's conspiracy.

Basic rotation

The basic rotation states of pieces is identical to Sega rotation, which was used in older Japanese Tetris games since 1988.

Some defining characteristics include:

  • All pieces except for the I-piece have its rotation states aligned towards the bottom of the piece's bounding box. This allows a piece to rotate after landing on a flat surface, without requiring floor kicks.
  • I, S, and Z-pieces only have two states, and rotating in either direction simply toggles their state.
  • Unlike Sega rotation, L, J, and T pieces can be rotated both clockwise, and counterclockwise.
  • The initial state of the L, J, and T-pieces have their longest flat side facing up.
Arika Rotation System's basic rotations.

Kicks

When basic rotation fails due to the piece colliding with the edges of the playfield or the stack, two kicks are tested.

The process is as follows:

  1. Basic rotation
  2. Kick 1 space to the right of basic rotation
  3. Kick 1 space to the left of basic rotation

In addition to these rules, there are some extra exceptions where certain kicks are not allowed.

  • The I-piece will never kick.
  • L, J, and T-pieces, from their 3-wide orientations, will not kick off their center column.

Center column rule

The center column rule prevents many unusual kicks which would otherwise be possible without the rule. Another side effect of the rule is that some rotations are not reversible, unlike with SRS.

L, J, and T-pieces use a 3x3 bounding box to hold the piece information, when referring to the center column, it means the center column of the bounding box. If any of these three pieces are rotated, an algorithm checks if the piece collides with the stack or playfield edges.

The algorithm for checking colliding blocks searches in the following pattern:

123
456
789

If the first block found in the search is a center column block (cells 2, 5, or 8), the rotation will fail. However, if the first block found isn't in the center column, and a kick is possible, then a kick is applied.

In the situations illustrated below if the X block is occupied.

.......X..
.LLL..LLL.
.LX...L...
..X.......
...L...XL.
.LLL..LLL.
.......X..
.JJJ..JJJ.
..XJ....J.
..X.......
.J....JX..
.JJJ..JJJ.
..X....X..
..I...III.
.III...I..

However, there are very similar situations where additional off-center blocks will enable a wall kick. In the situations illustrated below, the upper occupied blocks are off-center and enable the kick even in the presence of occupied blocks in the center column.

Clockwise rotation will successfully kick:

.X......X.
.LLL..JX..
.LX...JJJ.

Counter-clockwise rotation will successfully kick:

...X..X...
.JJJ...XL.
..XJ..LLL.

Kicks added in Tetris The Grand Master 3 Terror-Instinct

A number of kicks were added to Tetris The Grand Master 3 Terror-Instinct that eliminate common traps, and allow faster play.

I-piece wall kicks

In Terror-Instinct, the I-piece can kick walls and the stack. There are two different wall kicks.

GGZ.......
GGC.......
GGZ.......
GGZ.......

Try to rotate

GG........
XXCZ......
GG........
GG........

Basic rotation fails

GG........
GGZZCZ....
GG........
GG........

Kick 2 space right

........ZG
........CG
........ZG
........ZG

Try to rotate

.........G
......ZZCX
.........G
.........G

Basic rotation fails

.........G
.....ZZCZG
.........G
.........G

Kick left

Similarly to floor kicks, the I-piece needs to be touching part of the stack to kick one cell to the right.

G.Z.......
G.C.......
G.Z.......
G.Z.......

Try to rotate

G.........
XZCZ......
G.........
G.........

Basic rotation fails

G.Z.......
G.C.......
G.Z.......
G.Z.......

No rotation occurs

G.Z.......
G.C.......
G.Z.......
GGZ.......
G.........

Try to rotate

G.........
XZCZ......
G.........
GG........
G.........

Basic rotation fails

G.........
GZZZZ.....
G.........
GG........
G.........

Kick right

I-piece floor kicks

The I-piece can kick the floor, but it can be performed only once and cannot kick the floor in mid-air.

..........
ZZCZ......
..........
GGGG......

Fail

..........
..........
ZZCZ......
GGGG......

OK

..........
ZZCZ......
.G........
.GG.......

OK

There are 2 different types of floor kicks.

..........
..........
..........
ZZCZ......
G.........
GGGG......

Try to rotate

..........
..........
..Z.......
..C.......
G.Z.......
GGXG......

Basic rotation fails

..........
..Z.......
..C.......
..Z.......
G.Z.......
GGGG......

Kick 1 space up

..........
..........
..........
ZZCZ......
GGGG......
GGGG......

Try to rotate

..........
..........
..Z.......
..C.......
GGXG......
GGXG......

Basic rotation fails

..Z.......
..C.......
..Z.......
..Z.......
GGGG......
GGGG......

Kick 2 space up

T-piece floor kicks

The T-piece can escape from a hollow, up to two times.

G.........
G.I.......
GII.......
GGIGGGGGG.

Try to rotate

G.........
G.........
G.I.......
GXIXGGGGG.

Basic rotation fails

G.........
G.I.......
GIII......
GG.GGGGGG.

Kick up

Rotating a T or I-piece after it has floor kicked will permanently set the lock delay for that piece to zero. This is actually what prevents the second I floorkick. After the second rotation is processed, movement gets processed, allowing a shift of one cell left or right if it's done fast enough. Gravity is then applied. If the I-piece is not in contact with an occupied cell below after processing gravity, any attempt to floorkick will fail, as explained above. If contact does exist, the piece will instantly lock down, preventing rotation from being processed at all.

The T-piece has no such restriction, so it is possible to make it floor kick twice, but it will lock after the second one because there is no way to process rotation again before it locks.

Right side bias

In TGM's rotation system, the pieces rotate on only one axis resulting in asymmetrical rotations. In this example, the I-piece can't rotate on the left side of the stack;

..Z.......
..Z.......
..XGGGGGGG
..XGGGGGGG
.GGGGGGGGG


A situation which would work on the right side.

Notice the I has 1 rotation axis;

ZZCZ

I piece's rotation axis

For this reason it is recommended to build a well on the right side of the playfield, rather than the left. This bias is seen in other games, such as NES Tetris.

Mihara's conspiracy

Due to the right side bias with wall kicks, doing this move with a J when there is an empty hole right of the block that the J is caught on will lead to a hole.

L works:

..........
G...GG....
G.LLGGG...
G..L..G...
G.GLGGGG..
GGGGGGGGG.
GGGGGGGGG.

Firm drop

..........
G...GG....
G...GGG...
G.LLL.G...
G.1.GGGG..
GGGGGGGGG.
GGGGGGGGG.

Rotate left

..........
G...GG....
G...GGG...
G..LLLG...
G.GLGGGG..
GGGGGGGGG.
GGGGGGGGG.

Kicks to here

J in the other hand, does not.

..........
....GG...G
...GGGJJ.G
...G..J..G
..GGGGJG.G
.GGGGGGGGG
.GGGGGGGGG

Firm drop

..........
....GG...G
...GGG...G
...G.JJJ.G
..GGGG.1.G
.GGGGGGGGG
.GGGGGGGGG

Rotate right

..........
....GG...G
...GGG...G
...G..JJJG
..GGGG.GJG
.GGGGGGGGG
.GGGGGGGGG

Kicks to here

A block (marked as red) is required for the piece to do so.

..........
....GG...G
...GGGJJ.G
...G..J..G
..GGGGJGZG
.GGGGGGGGG
.GGGGGGGGG

Firm drop

..........
....GG...G
...GGG...G
...G.JJJ.G
..GGGG.1ZG
.GGGGGGGGG
.GGGGGGGGG

Rotate right

..........
....GG...G
...GGG...G
...G..JJJG
..GGGG.G2G
.GGGGGGGGG
.GGGGGGGGG

This fails too

..........
....GG...G
...GGG...G
...GJJJ..G
..GGGGJGZG
.GGGGGGGGG
.GGGGGGGGG

Kicks to here

This can be taken advantage of to rotate the J-piece over obstacles during 20G.

..........
....JJ....
....J.....
GGG.J.G...
GGG.GGG...
GGGGGGGGG.
GGGGGGGGG.

IRS counterclockwise

..........
.....JJ...
.....J....
GGG..JG...
GGG.GGG...
GGGGGGGGG.
GGGGGGGGG.

Move right

..........
..........
.....JJJ..
GGG...GJ..
GGG.GGG...
GGGGGGGGG.
GGGGGGGGG.

Rotate clockwise

..........
..........
..........
GGG...G...
GGG.GGGJJJ
GGGGGGGGGJ
GGGGGGGGG.

Place piece

In Tetris with Cardcaptor Sakura Eternal Heart, Mihara's conspiracy was fixed, and instead, pieces will only kick inward.

ACE-ARS and ARS2

Ace's rotation is a hybrid of SRS and ARS. Ace features guideline colors and lock delay is now directly reset by rotation/movement. A maximum of 128 lock delay resets are permitted per piece. Piece spawns that would previously have resulted in death (blocks occupying row 19/20 spawn locations) will now instead cause the piece to spawn higher, to a maximum of rows 21/22. This effectively makes the usable well size 2 rows higher.

ARS2 is available through an Xbox live patch for the game. Normal ARS features Sonic Lock (locking hard drop) and non-locking soft drop. ARS2 reverts these drop mechanics to how it worked in TGM3 and TGM2.

See also

References