Tetris The Grand Master 3 Terror-Instinct

Tetris The Grand Master 3 Terror-Instinct, abbreviated TGM3 or Ti, is a Tetris game from Arika, part of the TGM series. It was released in 2005 after 5 years of the second game. The game now runs on PC-based hardware, specifically the Taito Type X. The level system has been expanded in many forms with increasingly stricter requirements to reach the Grand Master rank. Modes include Easy, Sakura (a puzzle mode), the traditional Master mode, and Shirase (an extension of T.A. Death with even harsher speed, garbage, and levels beyond 999). It also features World (added by Arika due to The Tetris Company's recent policy changes) and Classic (TGM Rotation/ARS) Rules.

Difference from past games in the series
The grading system has undergone significant changes from previous games. The most notable change is the removal of an in-game score and grade display; they are only displayed after the end of the game, much like the secret grade in previous games.

Level Bonuses
Unlike in TGM, TGM2, and TAP, TGM3 advances the level further for a 3 or 4 line clear:

Easy
Easy mode has a number of similarities with Normal mode in TGM2. It is designed to bring less experienced players into the game who may be intimidated by the high speeds and steep learning curve of Master mode and Shirase mode. During play, the game displays a guide, depicted by a hollow frame, designed to give players suggestions on where to place the active tetromino.

The game also shows animations of fireworks every time a line is cleared. The total number of firework shots ("Hanabi") during play is given at the end of the game, and the express goal of the player is to attain the highest number of fireworks possible. The number of fireworks increase depending on numerous factors, including but not limited to higher line clears, combos (multiple consecutive line clears), and T-Spin line clears.

Easy mode is cleared by simply reaching level 200. Play continues during the credit roll in 20G, with a boost in the number of fireworks shown. Fireworks during the credit roll still count toward the player's total.

The exact formula for determining number of fireworks is somewhat complex. A thorough documentation of firework calculation behavior can be found here.

Speed Timings
The unit for gravity is G (rows per frame), as a fraction with a constant denominator of 256. This means G = Internal Gravity/256. For example, at levels 90 through 99, the gravity is 64/256G, or 1/4G.

Line ARE defines the number of frames of ARE to use after a line clear. The player's DAS charge is unmodified during line clear delay, the first frame of "lock flash" that occurs during the beginning of ARE without a line clear, and one frame of level-increment delay a little before the next piece spawns, and the frame a piece spawns.

Sakura
Sakura mode replicates the gameplay of Tetris with Cardcaptor Sakura Eternal Heart. The mode's objective is not to clear lines but to clear every jeweled block in each stage as quickly as possible, similar to Flash Point. There are 20 stages, and 7 EX stages, each progressively more difficult to clear efficiently. Some stages feature Items to handicap the player, such as the regular flipping of the playing field from left to right or the periodic invisibility of non-jewel blocks. The hold box is cleared between stages, thus it is not possible to hold a desired tetromino for the following stage. However, during the Ready! GO! sequence, the player may press Hold to move the next piece into the hold box; this may be done repeatedly to clobber the previous piece being held and force advancement of the piece sequence to a more desired position. The piece sequence in this mode is always predetermined, thus strategies can be formed ahead of time to aim for the fastest possible time.

Score is not recorded as the mode is purely a time attack exercise. The player has a time limit in which to complete the whole mode. Beginning at 3 minutes, a time bonus is given for quickly clearing a stage and for each jewel cleared. Each stage has its own further timer which is reset for each stage. If the stage time runs out, the player fails the stage but will be allowed to play the next one. If the main game time runs out, the game ends immediately. Topping out also ends the game.

The EX stages have no stage time; each must be completed in full to advance using the main game time. The number of EX stages offered after completing the 20 normal stages varies by the number of normal stages completed and time to completion. To be offered all 7 EX stages the main stages must all be completed (none failed) within less than 5 minutes.

Master
Master in TGM3 behaves very much like its predecessor in TGM2. Notable differences include the addition of a hold piece, a 3 piece preview. While these features aid the player, the increase in speed over TGM2 makes this game far more challenging. Unlike previous games, the rate at which the speed increases is variable, and changes according to how well the player is doing. For instance, depending on the player, the game may enter 20G as early as level 300 or as late as level 500. Master mode will stop at level 500 with no credit roll if the timer has exceeded 7 minutes (except during qualification exams where it will continue to 999 as normal).

Speed Timings
Clearing a section with a section COOL will boost the speed level by 100.

Line ARE defines the number of frames of ARE to use after a line clear. At this time it is not known whether the game has similar DAS behaviour during ARE as TAP does.

Grade Recognition System
Displayed Grade = floor(Internal Grade Boosts + Section COOL!! + Staff Roll Grade - Section REGRET!!)

As mentioned earlier, the player's grade is not displayed during the game but only after the game has ended. The invisible challenge during the credit roll is back in TGM3, but unlike TGM2, surviving it does not necessarily lead to a GM (Grand Master) grade. The earliest known GM grade was attained by the player 'jin8' on July 28, 2007. Only five other players have achieved it since. Many players had previously believed that the GM grade could not be obtained through standard play.

This system is also available in Tetris Best 2.

The Secret Grade GM is awarded for the secret "&gt;" stacking challenge in the same fashion as previous games in the series, and in Tetris Best 2.

There are three independent systems that work together to produce the final grade:

Internal Grade System
The first system is just like TAP, with internal grade points reaching 100 to advance to the next internal grade. Like TAP, the internal grade points are reset to 0 when this happens, wasting any remainder. Just like TAP's 9 -> S9, there are 18 grades this system can produce. In fact, testing by colour_thief (on his personal Ti machine set to freeplay) has shown that it is very likely that this entire part of the system is exactly the same as TAP with one important difference: the combo multiplier table.

The grade point formula is the same as TAP: Awarded Grade Points = ceil(Basic Amount x Combo Multiplier) x Level Multiplier

The basic amount and decay rate is determined by the player's current grade, and it is exactly the same as TAP. For each new "TAP grade" the player obtains, the player's grade gets a +1.

The combo multiplier is different from TAP. The values in each column are the same, but the columns themselves are in a different order, eliminating the odd behavior from TAP where consecutive triples may be awarded more than consecutive Tetrises. Most likely, TAP has the same table but an "off-by-one" programming error reads the values in the wrong order. This sort of error is very easy to make when accessing two-dimensional information from a one-dimensional array, as is the case with the combo table.

Finally, depending on the level, one of four level multipliers is applied to the awarded grade points. It is exactly the same as TAP.

Section COOL/REGRET System
The Internal Grade system is supported by a new COOL/REGRET grading system. Ti will display COOL!! or REGRET! for many reasons, but only one of these reasons is important to the grading system. The types in question are the "section COOL," which is achieved when the player reaches level *70 of all sections from 0-899 in a certain amount of time, and the "section REGRET", which is given out when the player finishes a section beyond a certain amount of time.

Getting a section COOL and finishing the section will result in a +1 modifier to the player's grade. It's important to note that the +1 modifier only takes effect if the section is finished, and that there is no section COOL in section 900-999. Though a section COOL is internally triggered at *70, it is displayed to the player from *82 to *99, depending on the level the player reaches first. If the player recieves a section COOL for the current section, then the next section's *70 must be reached no more than two seconds slower than the previous one to receive another section COOL.

Getting a section REGRET will result in a -1 modifier to the player's grade. A section REGRET will override a section COOL if both are received in the same section. If neither a COOL nor a REGRET are received in a section, no modifier is applied to the player's grade.

If the player misses a section COOL, then the following section's COOL conditions can be derived from the table below.

Staff Roll Grading System
The third and final grade system is only in effect during the staff roll. The staff roll in Ti works largely the same as in TGM2, but with a greater impact on the player's grade. Depending on whether it is the disappearing roll (where blocks disappear 5 seconds after they lock) or the invisible roll (where blocks disappear as soon as they lock), a grade modifier is put into place for the entirety of the roll.

The invisible roll requirements are to clear with all section COOLs and an internal grade of at least 27 (or S7 in TAP grading).


 * "Clear" denotes whether the player survived the staff roll or not.

User Accounts and Exams
A feature new to TGM3 is the ability to hold user accounts. When a player starts the game, they will be asked to either log in, create a new account, or play without using an account. Small advantages of this include not having to enter your initials at the end of every record-setting game as well as having a set of personal bests for each mode always on display in the top right corner of the play area.

The larger point of having user accounts is to assign each player a "qualified class" for Master Mode. In short, a player begins at the lowest class of 9, but if they consistently receive a grade in Master Mode higher than their current qualification, the game will randomly decide whether to give the player a "Promotional Exam" for a higher grade upon each new game. If the player passes, which is merely a matter of attaining that exam's grade or higher, then their new qualified class will be increased to that grade.

If the game decides to give the player a promotional exam upon the start of a new game of Master Mode, the tetrion will shake for a moment, the frame will turn gold and text will appear describing the class for which the player is receiving an exam. If the game ends for any reason, the tetrion will shake again and text will appear telling the player whether they passed or failed.

The player can also receive a "Demotion Exam" if the player isn't performing well enough for their current class. Its announcement is much more subtle than a promotional exam. It begins almost exactly like a normal game of Master Mode, but the tetrion will shake mildly at regular intervals during play. The objective is the same: The player must do well enough to get the grade that corresponds to their class in order to keep it. If the player does not make at least that grade, then their class will be reduced by one. The higher the player's class is, the easier it is to be demoted.

To be eligible for a Promotional Exam, the average of the player's second, third, and fourth best grades out of their last seven games (rounded down) must be higher than their current class. If an exam is given, then the class for which the player is being examined will be the aforementioned average.

GrandMaster Requirements
If the player exhausts the potential of all three grade systems (by reaching an S9 internal grade, attaining all nine Section COOLs, and earning at least six grade points in the invisible roll), the player will still only be awarded MasterM. The GrandMaster grade can only be first awarded through a Promotional Exam. Given the requirements to receive an exam, the player's best four performances in their last seven games must all be GrandMaster-worthy. Finally, in addition to clearing enough lines in the staff roll to get GrandMaster, the player must also survive it to pass the exam.

It is not necessary to be currently qualified MasterM in order to receive a GrandMaster promotion.

Once the player has a qualified class of GrandMaster, then the grade can be awarded in normal play, rather than being 'invisibly' converted down to MasterM. However, if the player is later demoted from GrandMaster, they must receive and pass a Promotional Exam again to return to receiving GrandMaster grades.

The Big Picture
As in TAP, overall, the grade/class system is far too complex and balanced to be strategized around in any significant way. The grade point system ensures that the player survives and makes high line clears while surviving, and the new COOL/REGRET system ensures that the player does not make any large mistakes and that they fix small mistakes as efficiently as possible. The relatively lenient COOL/REGRET conditions also emphasize that while a certain standard of speed must be kept in order to attain higher grades, the most important thing is to keep a pace comfortable enough that mistakes are few and tetrises are many.

Shirase
Shirase follows in the footsteps of T.A. Death in TAP. However, the immense speed difference is immediately apparent, and continues to increase throughout. Shirase mode does not stop at level 999 like in TA Death and Master mode, but continues to level 1300. Shirase also has other key features:

If the player reaches 500 with a time greater than 2:28:00 (Classic) or 3:03:00 (World) the game will stop, and the player is awarded the grade S5 (assuming no REGRET! deductions).

From level 500 to 1000, a line of garbage identical to the bottom row will spawn at regular intervals.

If the player reaches 1000 with a time greater than 4:56:00 (Classic) or 6:06:00 (World), the game will stop, and the player is awarded the grade S10 (assuming no REGRET! deductions).

From level 1000 to 1300, every tetromino that spawns is made of monochrome [ ] blocks. When locked these lack the usual bright colored outline that helps discern the shape of the stack, and they simply disappear rather than displaying a colorful explosion upon a line clear.

Grading is handled differently in Shirase mode. The game will award an S grade equivalent to the number of sections cleared; the highest grade being S13 for clearing level 1300. If the performance earns one or more "Section REGRETs" during play, the game will deduct a grade for each one. A REGRET! will be announced if a section time exceeds 1 minute.

The secret ">" stacking challenge applies to Shirase mode also, despite a significant increase in difficulty due to its speed. Secret grades awarded in Shirase mode start at m grades instead of the usual S grades.

The Shirase credit roll is a 20G, big tetromino challenge (all tetromino are twice their normal size).

Ichiro Mihara, creator of the series, has stated in his blog that level 1300 is in fact its own torikan and that it is possible to reach levels beyond 1300. This has since been disproven through reverse engineering the game's data, and verifying that no grades beyond S13 exist.

Speed Timings
Gravity is fixed at 20G.

Rising Garbage
From level 500 to 1000, the player will periodically receive single lines of garbage that duplicate the bottom row of the playing field. With each passing section, the rate at which this garbage is dealt increases.

For each piece spawned, a counter is incremented by one. For each line cleared, this counter is decreased by one. If during ARE the counter is equal to or greater than the section's quota, a line of garbage is dealt before the next piece spawns and the counter is reset to 0. Clearing lines while the counter is already at 0 will have no effect as the counter cannot go lower than 0. The counter is not reset between sections.

Scoring
Score in this game is even less important than previous games. The score is not shown until the game is finished, and it is not used for the grading system or rankings. Nevertheless, the algorithm has changed since TAP, eliminating any effect from bravos and reducing the reward for sonic drops and speed. The equation is:

Score = ((Level + Lines)/4 + Soft + Sonic) x Lines x Combo + (Level_After_Clear)/2 + Speed

Where:
 * Level is the current level the player is on.
 * Lines is the number of lines cleared. There is no bonus here for triples and tetrises.
 * (Level + Lines)/4 is rounded up.
 * (Level_After_Clear)/2 is rounded up. This is the only part of the equation where the level bonus for triples and tetrises makes a difference.
 * Soft is the cumulative number of frames during which Down was held during the piece's active time. Note that this means manually locking pieces already on the ground will increase the Soft value by 1.
 * Sonic is the size of the single greatest sonic drop during the piece's active time. Note that this is non-cumulative.
 * If the previous piece cleared no lines, Combo is reset to 1. Otherwise and its Combo value is:
 * Combo = (previous Combo value) + (2 x Lines) - 2
 * Example: A double-triple-single combo will have combo values 3, 7, and 7 respectively.
 * Speed can be no less than 0, and otherwise equal to:
 * Speed = Lock Delay - Active Time
 * Where, Lock Delay is the number of frames of lock delay given out for that particular level, and Active Time is the number of frames the piece was active (which is a minimum of 1).

Messages
When playing the game, certain text messages may momentarily show up below the playfield.

COOL!!
COOL!! messages appear only in Master mode. There are currently 3 known triggers of the COOL!! message. They cannot be visually distinguished, but they are known to show up when certain conditions are met. All names below are unofficial.

"Section COOL"
A "Section COOL" appears at around, but not exactly on, level *80 when the player has reached level *70 within a specific time. It may appear right before a piece spawn, or along with a line clear.

The player's grade is incremented by 1 when they finish a section after having triggered a section COOL in that section. As an exception, a section COOL does not appear in the 900-999 section. No other types of COOLs influence the player's grade.

"Tetris COOL"
A "Tetris COOL" appears when the player has made a certain number of Tetrises during a section. The required number is 3 times in 0-99, 6 times in 100-199, and 4 times in all subsequent sections. Tetrises that span across sections are not counted for either the previous section or the new section. This means that for a Tetris to count towards a "Tetris COOL", the move must occur by level *93.

A Tetris COOL can be triggered twice in the 0-99 section if the player makes 6 Tetrises, double the number required to get it once. In other sections it is practically impossible to make double the number of required Tetrises, and likely harmful to the player's grade. 12 tetrises in a section is completely impossible, and 8, while theoretically possible, will require enough pieces for a 16 row high stack at the previous level stop (risking a "Section REGRET"), and only leaves about 8 to spare on the level counter.

"Special COOL"
A "Special COOL" appears approximately two seconds after when the player performs certain moves:


 * more than 3 Tetrises in a row, one right after the other
 * more than 2 T-Spins in a row, one right after the other
 * a T-Spin Triple (WORLD only)

The T-spin conditions can stack up. Therefore, if the player makes a T-spin Triple immediately followed by a T-spin Single, they will get two COOLs in a row.

REGRET!
REGRET! messages note a failing in the player's performance. There are 2 known kinds of REGRET! messages in the game. In addition to Master mode, REGRET!s can also show up in Shirase mode. Again, all names are unofficial.

"Section REGRET"
A "Section REGRET" appears when the player takes longer than a set amount of time to get through a *00-*99 level section. Some examples are 1'30" for Master mode Lv. 0-100, and 1'00" for Shirase mode Lv. 0-100. The times are the same for both Classic and World rule modes. When a "Section REGRET" appears, the player's grade will be decremented by 1.

"Hole REGRET"
A "Hole REGRET" appears when the playfield is in a suboptimal state, such as with numerous holes and possibly steps in the landscape; the exact mechanics of this detection are undocumented. It appears immediately after locking a piece, or clearing a line. These can happen multiple times per section, and do not affect the player's grade.

T-SPIN!
These messages can appear in any mode, and simply indicate that the player has just cleared a line(s) with a T-spin. Unlike most other games, the requirements for a move to be considered a T-spin are extremely lenient; the player simply has to clear one or more lines with a T tetrimino where the last move performed was a rotation; there are no wall or corner placement rules.

Codes
Key: L = Left, R = Right
 * Big Mode: LLRRLRLR

This code only works when the player has not loaded any account data; thus, records achieved in this mode are not saved. The code is entered at the mode select screen before selecting Master mode.


 * Random Piece Sequence: A+B+C+D

This code only works on an account that has completed Sakura mode before. Hold down all 4 buttons as you select Sakura mode to get a random piece sequence instead of the predetermined one.