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.

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 many 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, creating a "game within a game," where the objective is to attain the highest number of fireworks possible. The number of fireworks can increase with 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.

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 handicaps 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, therefore; it is not possible to hold a desired tetromino for the following stage.

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.

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 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 GM grade was attained by the Japanese player 'jin8' on July 28, 2007 and 'KAN' on Dec 27, 2007. It was also acheived by 'DIS' at an unknown date. They are currently the only players in the world to have achieved GM. Many players had previously believed that the GM grade could not be obtained through standard play.

The Secret Grade GM is awarded for the secret ">" stacking challenge in the same fashion as previous games in the series.

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. 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 than TAP. The same columns are used, but are given to different line clears. Most likely, TAP uses the exact table below 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 to 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". In short, when a player consistently receives a certain grade in Master Mode that's higher than their current qualification (which starts at class 9), the game will randomly decide whether to give the player a "Promotional Exam" for that grade upon each new game. If the player passes, which is merely a matter of attaining that grade or higher, then their new qualification will be 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.

The only internal condition that must be satisfied in order to be eligible for a promotion is that the average of the player's best four grades out of their last seven games 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, the player will still only be awarded MasterM. The GrandMaster grade is only first awarded through a promotional exam. To be eligible for this exam, the player first has to be qualified MasterM, then they must consistently achieve GrandMaster-worthy performances until the exam is given. In addition to clearing enough lines in the staff roll to get GrandMaster, the player must also survive it to pass the exam.

As long as the player is qualified GrandMaster, then the grade can be awarded in normal play.

The Big Picture
Overall, the grade/class system is far too complex and balanced to be strategized around in any significant way. Like in TAP, 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 TA 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.

Ichiro Mihara, creator of the series, has stated in his blog that levels beyond 1300 exist. Methods to reach such levels are yet unknown because the 1300 barrier has not yet been broken, even at the current (as of May 2008) record clear time of 4 minutes and 19 seconds.

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 time" REGRET! during play, the game will award an S grade lower than the number of sections cleared. REGRET! is announced if a section time exceeds 1 minute. Although there are other types of REGRET! confirmed, only the section time REGRET! appears to subtract from the player's grade.

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).

Speed Timings
Gravity is fixed at 20G.

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 apparently 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 cummulative number 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-cummulative.
 * 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).

COOLs and REGRETs
When playing the game, certain text messages may momentarily show up below the playfield. Two of which, COOL!! and REGRET!, are known to appear when the player has fulfilled certain conditions.

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 each show up when different conditions are met.

Tetris COOL
A "Tetris COOL" appears when the player has made Tetrises in excess of a certain number of times. The required number is 3 times for 0-99, 6 times in 100-199, and 4 times for all subsequent sections. Tetrises that span across sections are not counted for the previous section or the new section. This means that for a Tetris to count towards a Tetris COOL, the player would need to make the move 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 perhaps even 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 time REGRET), and only leaves about 8 to spare on the level counter.

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.

It is strongly suspected that the player's grade is incremented by 1 when he finishes 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.

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, he will get two COOLs in a row.

REGRET!
REGRET! messages appear to 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.

Hole REGRET
A "Hole REGRET" appears when the playfield is in a suboptimal state, namely with numerous holes and possibly steps in the landscape. It appears immediately after locking a piece, or clearing a line. It can happen multiple times per section.

Section Time REGRET
A Section Time REGRET appears when the player took 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 same for both Classic and World rule modes.

Effects on Grading
Section COOLs and REGRETs strongly affect the final grade. All other COOLs and REGRETs have no direct impact on the grade.

Codes
Only one code is known for TGM3. It can only be entered when no player data is being used, and should be entered at the mode select screen. It is known not to not work in all modes.

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