Ichiro Mihara was first inspired to create a Tetris game after watching a Japanese game show where contestants would compete in Tetris. The versus mechanics of the game used by the show did not look very interesting and he thought he could do much better. After Arika developed a prototype and shared it with the show's producers, they flatly rejected it on the grounds that "it was too complicated, Tetris should be an elegant and approachable game." This feedback then inspired Mihara to instead develop the streamlined and elegant TGM series. While the original prototype versus game has never been shared publically, the core ideas were reused for the TGM series' versus mode. Because of this unique heritage, TGM has a rich and exciting (if complicated) versus system despite primarily being a simple and polished single player game.
Overview
The biggest distinguishing feature is the 100% deterministic tactical garbage system, which gives players full control over what garbage is sent to their opponent. Players receive identical piece sequences using the TGM randomizer, further reducing random factors.
It also features a large number of items, which come in attack, defense, and neutral varieties. In addition to item effects, attack items will also destroy an opponent's active piece, allowing deliberate piece sniping as a mechanic. The items, often criticized by new players as being overpowered and unfair, have a surprising amount of depth to them and their impact can be mitigated or amplified in the hands of an experienced player. While they do introduce a degree of randomness, there is a system to the randomness that makes it is more balanced than it may at first seem.
The pace of matches is slower than many popular versus Tetris games, due to ARE and a long line clear delay. Despite this, popular modes with 20G such as T.A. Death and Shirase are so difficult that players are at risk damaging their board just as much as their opponent is.
These elements combine to place a focus on dynamic interactions between players rather than a tug of war over raw speed. Screen reading is required for high level play, with important examples including:
sniping a valuable piece or item block
reading which columns your opponent is vulnerable to garbage in
reading where your opponent is about to send you garbage so you can keep those columns stacked low
timing item activation for maximum effect
stacking in a way minimizes the damage your opponent's item will cause
In order to keep games relatively short, there is a time limit of 2 minutes and 40 seconds per round as well as a level limit of 200. Most rounds end in a player dying, though reaching the level cap first will also secure a victory. If the time runs out, the win goes to the player with the highest level count. In the unlikely event of simultaneous death, simultaneously hitting the level cap, or having tied levels when time runs out, the round will end in a draw which is effectively treated like a win for both players giving them each a point for the round. The winner of a set is the first to win 2 rounds. In the unlikely event that a draw awards the winning point to both players, the defending player (the one who was playing a credit before a challenger came) will be declared the winner. The time limit/level cap and number of rounds may be modified in the service menu.
Tactical Garbage
Mechanics
Singles send no garbage. Line clears that activate items send no garbage. Everything else sends 100% deterministic garbage following simple rules: Take the line clear, erase the clearing piece, and send it vertically flipped to your opponent (compare Bloxeed which is similar but does not flip the garbage hole). To illustrate this, see how the line clears (left) create the final garbage pattern (right):
Note that if your line clear results in a perfect clear, you will double your attack power by sending the same garbage pattern to your opponent twice. Since TGM does not use the 7-bag randomizer, perfect clear openers aren't a viable tactic and in general perfect clears almost never happen.
There is a limit to how much garbage can be queued up to attack your opponent. The first 8 lines will be sent, and anything beyond that will do nothing. This is extremely unlikely to occur unless your opponent is stalling at low gravity, or you do something ridiculous like combo into a Tetris perfect clear.
There is also a limit to how high your stack is. If garbage pushes your stack above row 21, anything that would otherwise have occupied rows 22+ is forgotten. If you manage to clear lines and lower your stack again you will find that these spaces are now empty.
Garbage Efficiency
The strategy for maximizing the amount of garbage you send per piece is relatively simple. You should avoid singles, even while downstacking, as much as possible. If you do take a single, it should be when you have an uncomfortable position and it really helps you to downstack more efficiently.
There is an exception to the no-singles rule. The line clear that activates an item does not send garbage. To keep garbage efficiency as high as possible, the best strategy is to activate items with singles. If you do take a larger line clear while activating an item, it should be because you either really need it for downstacking or that the timing of the item activation is tactically powerful. See the item section and sniping for some opportunities.
Mix Ups
There is no specific bonus for a Tetris or T-spin. They are all equally efficient in terms of sending garbage lines. Despite the slow line clear animation, it is generally favorable to clear doubles, while mixing up the columns as much as possible. The extra inconvenience to your opponent in downstacking more than makes up for the line clear animations you suffer. The reason doubles are preferred over other line clears is that you can do more mix ups per unit of material on the screen. Given 6 lines of material, 3 doubles can mix up over 3 different locations whereas 2 triples can only mix up over 2 locations.
Consider the trivial hole from a Tetris:
Now compare it to the damage dealt by 2 skim doubles:
The above illustrates the effect of a small mix up, spread over 3 nearby columns. More generally, if you can clear doubles in a faraway column, it will be even more powerful. It's worth making an effort to spread your doubles around as long as you don't sacrifice your board stability or too much speed. Mix ups are extremely improvisational, an intuitive sense for the opportunities is more effective than memorizing setups.
Tier List
The different possible clears and their corresponding garbage patterns have emergent value depending on their mix up potential and how annoying they are to deal with. Garbage patterns are better if they:
Allow you to do more mix-ups per line cleared.
Force your opponent to make multiple line clears to dig through them.
Force your opponent to upstack to maintain garbage efficiency, or else clear singles.
Force your opponent to avoid overstacking in as many columns as possible.
Note that while a T-spin is perfectly fine for this, it is not required. Simple T-doubles are just as effective.
Being a double, it has great mix up potential. It is also powerful because the hole shape needs at least 2 separate line clears to dig through, and both times the opponent will need to upstack if they want to maintain garbage efficiency by converting it into a double. The player must also be careful about overstacking in 3 columns.
A Tier
This garbage has most of the advantages of the T-double, with mix-up potential of doubles and a jagged shape requiring 2 clears both of which require upstacking to maintain garbage efficiency. Unlike with S-tier, your opponent only has to worry about overstacking in 2 columns.
B Tier
This garbage has most of the advantages of A-tier, but as a triple there is less opportunity for mix ups. The jagged shape still requires 2 line clears, but a double is directly available meaning that upstacking is only required in 1 of the 2 line clears to maintain garbage efficiency. Your opponent again only has to worry about overstacking in 2 columns.
C Tier
This garbage has the mix up potential of doubles, which is nice. This big drawback is that the hole shape can be filled with 1 line clear, using the L and J kicks shown below. These kicks also only require being mindful of overstacking in 2 columns.
D Tier
While these clears are useful for mix-ups, the big drawback is that they can be cleaned up in 1 clear without upstacking. Their only saving grace is that they force your opponent to avoid overstacking in 3 columns.
E Tier
These holes can be handled in 1 line clear without upstacking, but this time they only need your opponent to be mindful of overstacking in 1 or 2 columns. Since it is weak in isolation, this garbage is best used as part of a mix up. Situationally, the O double can be decent in openers to disarm your opponent's Tetris hole. However, since good opponents will not go for a Tetris hole opening this counter has low value.
F Tier
Unless you're clearing these to counter garbage that your opponent has sent you, these are clears you want to avoid at all costs. They are easily countered with 1 line clear and no upstacking, and only require avoiding overstacking in 1 column. If they have any place at all it is to apply pressure to an opponent who has so much other garbage that they are unlikely to ever open this hole, though a 180° field can potentially open this up to a counter.
Item System
At the start of each round you begin with an empty item meter in the center of the screen. With each piece that spawns on your screen, the meter will charge up slightly. After 20 pieces, the meter will be fully charged and the 21st piece will be a randomly selected item. Clearing a line which contains an item piece will activate the item's ability. The game will continue to cycle like this, 20 non-item pieces followed by an item piece, until the round ends. Note, however, that while you are attacking your opponent with an attack item, none of your piece spawns with charge your meter until the attack is completed.
Both players start each round with their own bag containing one of each item. Items are randomly drawn (according to their probability weighting) without replacement. On default settings with a level cap of 200 a player will empty less than half of their item bag, making some items extremely rarely seen. Before any items are dealt, the sum of the weights of the bag add up to 1970. So the probability of getting a Color Block as your first item is 250/1970, whereas getting a Nega Field is 250 times rarer. As the bag gets emptied of heavily weighted items, rare items become more probable. Most matches will open with relatively benign items, ramping up slowly with defense items more common in the mid game, and with the most overpowered items only making an appearance near the end of the 200 levels if at all.
TAP Item Summary
Item Name
Type
Counterable?
Weight
Initial Probability
Color Block
Attack
250
12.7%
Laser
Attack
250
12.7%
Transform
Attack
Yes
250
12.7%
↑ Del Field
Defense
250
12.7%
Del Even
Defense
150
7.6%
Mirror Block
Attack
Yes
150
7.6%
Roll Roll
Attack
150
7.6%
X-Ray
Attack
150
7.6%
180° Field
Attack
Yes
100
5.1%
↓ Del Field
Defense
100
5.1%
Death Block
Attack
50
2.5%
Hard Block
Attack
50
2.5%
→ Mov Field
Defense
50
2.5%
Dark Block
Attack
5
0.3%
Shotgun!
Attack
5
0.3%
Exchg Field
Neutral
Yes
3
0.2%
Freefall
Neutral
3
0.2%
← Mov Field
Defense
3
0.2%
Nega Field
Attack
1
<0.1%
If you neglect to activate an item for 20 pieces so that the meter fills again and another item spawns, it is possible to have more than one item block on your screen. However the moment you activate an item all other item blocks on your screen will turn into regular blocks. This includes items blocks that which appear in your next piece preview but which have not yet spawned. Therefore, if you want to spike item activations, you should activate the first item when the meter is 19/20 pieces full. Note that since the item meter does not charge while an attack item is active, you will place several pieces before you can complete the last charge of the meter.
In TGM3, there is another way to lose an item: when you Hold an item block, it will turn into an ordinary piece.
Attack Items
Attack items have several universal effects in addition to their individual item gimmicks. When you activate an item, it destroys your opponent's active piece (assuming they are not in the middle of ARE). This is especially useful if you tactically snipe an important piece from your opponent. Attack items also show a cut-in animation on your opponent's side, delaying them for a moment. This is particularly valuable in high speed matches like T.A. Death where it buys you a few pieces of time free from attacks from your opponent. These properties turn even the weakest attack item into something which is useful.
There is one drawback to activating an item: while your attack is active, your item meter will not charge (though your opponent's meter will). The duration of this active time is something that varies on an item by item basis. It is always at least as long as the cut-in animation, but it can be longer. For example, with Transform, Roll Roll, and Mirror Block you do not charge meter until your opponent has placed all 3 pieces. Inconsistently, with Death Block and Hard Block your meter will be able to charge the moment the cut-in animation ends.
If a player clears a defense item or neutral item block while an attack item is active on them, these items will not activate until after the attack is complete. This attack item "active time" is the same as for the item meter blocking effect.
Color Block
This item will shimmer your opponent's stack different colors briefly. Even beginners are not intimidated by this item, so it is unlikely to slow your opponent down beyond the cut-in animation's effects. To maximize this item's impact, it is best to deliberately snipe an important piece, otherwise it essentially does nothing.
Laser
The Laser is unique among attack items for not really having an a true cut-in animation. Instead, a pulsating target will appear at the top of a column. After a brief delay, the targeted column will be completely cleared. If the player's stack is high on the screen it can be particularly devastating.
Watch out for your opponent getting items such as Mov Field which will undo the Laser damage. In this case, it is better to activate Laser after the Mov Field has been activated.
The damage may be amplified by making sure your opponent's stack is as high as possible. This means converting your existing screen material, particularly a tetris or triple, to garbage before activating the Laser. Likewise, if the receiving player has some line clears set up you will benefit from activating the Laser before they have a chance to clear them.
Another possibly devastating amplification is use the Laser to snipe the I piece, with the Laser hole creating a dependency on the I piece while it is in the randomizer's piece history and unlikely to appear for at least 4 pieces. Note that you can force the Laser to target the middle of the screen with excellent timing, as explained below, by making sure to snipe a piece right as it spawns.
These amplifications should be used with caution if your opponent is screen watching, as it gives them extra time to prepare (also explained below).
While the Laser is notorious among beginners as an item that will kill them quickly and unfairly, the defending player actually has a huge amount of control over it. The targeted column can be controlled. It is the leftmost column of the piece that was sniped, or else the leftmost column of the most recently placed piece. It is therefore really important for defenders to screenwatch their opponent, and to align their piece over a favorable column.
This player, oblivious to an incoming Laser, tries to stack left. They are punished, and the Laser hole will likely be their death.
This player has reacted to the incoming Laser, and moved the piece over their highest hole. The Laser opens up this hole, and they are in a reasonable position to survive.
As an attacker, if your opponent is advanced enough to screenwatch you and react, counterplays become possible.
This player has reacted to the incoming Laser, and moved the piece over their highest hole. However, the attacker saw this, and held off activating the Laser. Instead, they timed it to snipe the following piece before it could be moved, causing devastating damage to the stack.
Once the column has been targeted, the Laser can be further influenced. There is an 80 frame window where you can mash left or right to nudge the Laser horizontally. For every 3 taps in a certain direction, the laser will move 1 column in that direction. To successfully tap, there must be an "off" frame to distinguish the separate presses, so ~30Hz would be the maximum theoretical rate. A practiced player should be able to move the Laser 1-2 columns without trouble, or 3 if they are very good. Perhaps Takahashi Meijin would be able to move it 6 columns.
This player has just done a T-spin, and a Laser was activated during their ARE. Instead of taking the Laser in column 3, they mashed left 6+ times which nudged it over to column 1, creating a much more favorable position.
There is a final way in which the Laser can be manipulated. During the 80 frame period, you can mash the A, B and C buttons to widen the Laser to 2 or more columns. For every 10 presses, the Laser will widen by 1 column. Note that this button mashing is possible at ~60Hz since you can alternate buttons. The easiest technique is to piano roll CBA in a tight loop. The center of the Laser does not change, but it will grow outwards alternating right-left-right-left. During this same time, the attacking player can mash CBA as well, and for every 15 presses, they will prevent one unit of widening of the Laser. In practice, fighting with the defending player over the Laser width is probably not worth it because placing 2 pieces during the 80 frames would be better.
This player has just done a T-spin, and a Laser was activated during their ARE. Instead of taking the Laser in column 3, they mashed CBA 7-9 times widening the Laser over columns 2-4 and creating a much more favorable position.
Note that it is possible to simultaneously move and widen the Laser if you are dexterous enough to mash directions and rotations at the same time.
Transform
The Transform item makes it so that when you rotate a piece, it randomly transforms into one of the 7 piece types. It is only affected by rotations that happen during Active Time. This means that if the defending players reacts quickly enough, they can IRS the piece to access 3 of the 4 possible piece orientations. An opponent caught off guard may waste a lot of time switching through different pieces until they get a reasonable match, but for a strong player it won't even slow them down.
It should be noted that as you switch through the random pieces the rotation state is preserved. This means S, Z, and O pieces (with 2, 2, and 1 visible rotation states respectively) actually have a full 4 rotation states. How the different pieces line up with each other as they transform can be seen by looking at the columns of the basic rotation table below.
The order of operations is to transform a piece and then attempt to perform the rotation on the piece. There is a certain logic to this process that adds a degree of predictability:
If the pre-transformed piece cannot be rotated, then no rotation or transformation happens.
Before any rotations are applied, the transformation picks a candidate piece from the 7 piece types in a pure random way. It attempts to spawn the chosen piece, similar to jumping from one piece to another in a single column of the above rotation table. Notably, in trying to fit the candidate transformed piece the game will apply ARS wallkicks during this spawn process. If this fails to find room for the candidate piece, the transformation is aborted and the piece stays untransformed. Otherwise the piece is transformed, with the position shifted according to any kicks.
Finally, the rotation is processed applying any ARS kicks if applicable. If the piece transformed but the new piece type cannot rotate, the transformed piece simply stays in place without rotating. If the transformation spawn did a kick and the rotation also did a kick, it is possible that the piece kicked twice in one frame.
For a piece rotating freely in the air that logic does not matter, but on the ground or against a wall there are some emergent patterns from this system.
It is possible to force an I piece transform in low gravity. Since the original piece must be able to rotate for anything to happen, and a vertical I piece against a wall cannot rotate, then DAS'ing a piece to the wall and repeatedly triggering transforms will eventually get the piece stuck as an I piece unable to transform further. Every 2 rotations there is a 1/7 chance of it becoming an I piece. If you piano roll CBA quickly 4 times, it will cycle through vertical rotation states 6 times and be expected to successfully transform into an I piece ~60% of the time. After mashing CBA 8 times this increases to an 84% success rate.
After DAS'ing to the wall, the player began mashing CBA. After the first third rotation, the piece has transformed into a vertical I piece and all subsequent rotations have no effect. They can repeat this process on the next piece to apply some serious pressure to their opponent.
There are also a couple wallkicks which are 100% guaranteed not to transform the piece. Consider this L kick:
All alternative candidate transform pieces will fail (even after considering their kicks) forcing the piece to stay an L piece.
By a similar argument this J kick is guaranteed to work:
There are no other known kicks that are 100% safe. For example, a T-spin will usually work but there is a 1/7 chance of it transforming into an S or Z piece, depending on the rotation direction.
Mirror Block
For 3 pieces, the Mirror Block attack will flip the player's screen horizontally. The flipping animation takes time, making this an item that slows down an opponent more than the usual attack item.
One thing to be aware of is that the item gives the player access to some easy mix ups. With each screen flip, the holes get moved around, giving the potential for 3 easy mix ups if line clears are available. In the worst case, 1 mix up is guaranteed since there are an odd numbers of flips.
Roll Roll
For 3 pieces, the Roll Roll will turn pieces grey and make them automatic counter-clockwise rotations every 30 frames. It is not unusual for even experienced players to slow down significantly to avoid a misdrop, and at high speeds it is very likely to cause some damage.
Mitigation of the attack involves making adjustments to account for the automatic rotations. Depending on the placement's piece orientation and how fast you expect to place it, a different adjustment is required. A fast placement is one where you will place the piece within 30-59 frames of active time, and a slow placement is one where you will place the piece within 60-89 frames of active time.
Roll Roll Input Adaptations
Desired Orientation
Placement Time
Roll Roll Adjustment
Neutral
Fast
B
Neutral
Slow
AC
CCW
Fast
-
CCW
Slow
B
180
Fast
A
180
Slow
-
CW
Fast
AC
CW
Slow
A
X-Ray
Despite the name X-Ray, this item operates more like a radar scanner. The defending player's screen will go dark, and it will be illuminated one column at a time from left to right.
While slightly more disruptive than Color Block, the effect is still relatively minor and is unlikely to significantly delay your opponent.
180° Field
This item flips the field over, taking the top non-empty row and swapping it with the bottom row etc. There are opportunities for both attacking and defending players to screenwatch to control the damage. If this item is timed too late when sniping a piece, you can bury your opponent's item block which can be almost as good.
Here an attacking player did not attempt to maximize damage. They activated the 180° Field immediately, sniping the defending player's I piece.
The resulting damage is very minor.
Here the attacking player read the likely vertical I piece placement, and waited for the defending player to place the piece.
The resulting damage is much more severe.
The attacking player should be extra careful: There are also many positions where a defending player would happily accept a 180° Field. In particular note, that the flipping of the screen is guaranteed to open up access to the garbage and it will also convert the most difficult garbage patterns into much easier patterns. This opens up an opportunity for the defending player to damage spike the attacking player.
Here the player is upstacking so that they can downstack with a double. They are at least a few pieces away from doing this.
They now have immediate access to clear doubles, and the holes are much simpler.
The correct play for the attacking player in these situations is to delay the activation of the 180° Field, at least until the defending player already has access a doubles clear. If this double is not a column mix up, you may even want to let them clear it before activating the item and giving them access to a free mix up.
Death Block
This item makes the defending player's next piece extra large, just like in Big Mode. You can maximize your damage by selecting a particularly inconvenient piece. The best choice is a piece that forces your opponent to overstack, allowing you to apply pressure while they are prevented from downstacking.
Here the attacker was not screenwatching and activated the item immediately. The defending player opts to put the big I block horizontal.
The next piece was an O block. The resulting double fully nullifies the Death Block attack and even sends garbage back to the attacker.
Here the attacker was screenwatching and chose not to activate the Death Block on the I piece. Instead they sniped it and activated Death Block on the following O block.
In general, a big I piece is quite easy to clear and a big O piece will force 4 rows of overstacking. Even with a smooth 4-wide surface for the O block, 4 rows of upstacking are quite a lot of pressure. S, Z, L, J, and T pieces can situationally be effective but the defending player's stack shape could give them some good options. To build intuition on which big piece are inconvenient on a certain stack, you should practice Big Mode.
Hard Block
This attack will encase the defending player's next piece in a hard metallic shell. Lines cleared will break the shell, revealing the original block underneath. Any lines which break the shell do not count as lines for the purposes of sending garbage. This means that in addition to causing holes, Hard Block will also hurt garbage efficiency. Attacking players cannot particularly amplify the damage with screenwatching, though you may want to consider delaying activation if it would make an I piece the Hard Block, particularly if there is a good horizontal placement for it. Also watch out for ↑ Del Field which will effectively cancel the Hard Block attack.
How you stack the Hard Block is very important. You will suffer less damage with placements that occupy fewer rows.
Here a player treats the Hard Block like any other block.
They clear lots of material while sending 0 lines of garbage. At the same time, they have not made any progress downstacking and have made a huge hole.
Here the player tries to minimize the damage by placing the I piece horizontally, even though this covers their Tetris hole.
The Hard Block still hurt garbage efficiency by forcing 2 singles, in the end this is dramatically better than the alternative.
Another mistake to avoid is partially clearing the Hard Block, filling in the hole, and then clearing more of the Hard Block.
This board is now in a really difficult position, despite picking placements that feel very reasonable had there been no Hard Block.
By contrast, consider what happens when the Hard Block is fully cleared at once.
The board is still uncomfortable, but there is greater hope of returning to a strong position without needing to ruin garbage efficiency or do upstacking.
Dark Block
This is the ultimate form of the cosmetic attacks. The defending player's stack will disappear similar to the m-roll of Master Mode. While more effective than Color Block or X-ray, it is unlikely to cause serious damage against a strong player. It's most effective against a complicated stack shape that will be difficult to remember, however it's probably not going to be worth screenwatching in an attempt to wait for a screen to become unmemorable. Players generally stack pretty flat in VS anyways, so you could be waiting forever.
Shotgun!
This item is completely overpowered, but is so rare you are unlikely to see it much in practice. Every row gets one random column selected (1 through 10, pure random), and the location is cleared of blocks. The random column selection is not limited to filled spaces, so if the randomly selected space happens to be empty no damage will be received in that row.
Here severe damage is demonstrated even on a reasonably low stack/
Note that rows 1 and 6 did not receive holes. Empty spaces were randomly selected in those cases.
Nega Field
This item is even more overpowered than Shotgun!, but is also even rarer. For every row up to the highest populated row, every cell with a block changes to a hole and ever cell with a hole changes to a block.
Here severe damage is demonstrated even on a reasonably low stack.
Note that it stopped at row 6. In weird cases where you have some blocks floating above completely empty rows, those empty rows will be converted to lines.[1]
Defensive Items
↑ Del Field
This item will delete the top half of your board (rounded up). It's very useful for getting rid of a Hard Block or Death Block attack.
If you're winning and want to continue applying pressure, you may want to avoid losing material to ↑ Del Field. In this case it's possible to spike your stack to avoid this.
The player can now send reasonably send 2 doubles to apply a killing blow to their opponent.
Unless you are clearly winning, it is recommended that you save this item as long as possible to maximize your value out of it. The longer you save it, the more garbage your opponent can send you only to be cancelled.
Del Even
This item will clear all even rows. Like most defensive items, you will maximize the value by delaying it's use as long as possible or until you really need it.
If your garbage is focused in a few columns, it will tend to simplify it.
If your garbage has a lot of double mix ups, you will have an awkward collection of single holes and downstacking will be difficult without hurting garbage efficiency.
↓ Del Field
This item will delete the top half of your board (rounded up). If you want to maximize the effect of ↓ Del Field, you may want to spike your stack.
Here a player immediately activates the item.
Notice how 3 separate garbage mix ups are still on screen.
Here a player spikes to amplify the item effect.
Notice how only 1 double's worth of garbage is still on screen.
→ Move Field
This item moves all the blocks to the right, leaving the hole on the left. It is a very powerful recovery and allows you to apply strong pressure against your opponent afterwards, though you won't be easily able to mix up.
← Move Field
This item moves all the blocks to the left, leaving the hole on the right. Just like the more common → Move Field version, it is a very powerful recovery and allows you to apply strong pressure against your opponent afterwards, though you won't be easily able to mix up.
Neutral Items
Exchange Field
This item swaps the 2 players' playfields. If the defending player has an item block on their field, it is converted into a normal piece rather than being stolen by the attacked. A safe option, if you are clearly losing, is to use the item before your opponent has time to react. Other situations are more complicated as detailed below.
The basic strategy, when your opponent isn't screenwatching, is to wreck your stack before you swap. If you do this, you should make sure to do it in a way that is unlikely to actually put you in immediate danger or risk cutting off access to the item clear.
Note that if the defending player is screenwatching, they also have the option to destroy their own stack in the same way.
These self-destructive strategies are not game theoretically stable. They only really work if one of the two players isn't reacting to the item. Otherwise, the recommended actions are:
Exchange Field Action Map
Advantage
Attacker Actions
Defender Actions
Attacker
Hold off on the item and keep sending garbage.
Play normally until the advantage is neutral.
Neutral
Hold off on the item and keep sending garbage.
Maintain a neutral advantage while still playing as fast as possible. Don't attack your opponent unless they attack you.
Defender
Activate the item immediately to take advantage.
Destroy your own board position until the advantage is neutral.
Note that both players should still be playing at their max speed. For example, if the attacker is stalling in the neutral stalemate the counterplay is for the defending player to quickly clear singles to maintain the neutral position while still advancing their level counter. This will allow the defending player to win by level count.
Free Fall
Screen Reading
Harassment
If you screen read your opponent and notice they have stacked a particular column too high, you can harass them.
Player 1 has stacked high in column 1, whereas Player 2 has kept a flat stack to keep options open.
Player 2 can screen read and harass them by clearing lines in column 1.
Player 1 is now seriously overstacking their garbage and it will take a while to downstack though it.
Counters
If you see your opponent building up to a line clear, especially something telegraphed well in advance like a Tetris, then you can anticipate where your garbage will come from. By leaving those columns accessible, you can immediately send the garbage back to them. This is especially true if you are playing slightly slower than your opponent. Since both players receive the same piece sequence, you will literally get the I piece immediately after your opponent clears a Tetris.
Player 2 is waiting to see what Player 1 is up to before committing to a placement.
Looks like Player 1 will send lines on the right. Player 2 decides to stack for a double while leaving columns 9 and 10 otherwise open.
Still 2 pieces behind, Player 2 is ready to send a double while Player 1 is sending a Tetris.
2 pieces later, Player 2 is poised to send the Tetris right back to Player 1.
Player 2 is now at a superior advantage despite playing slower. They have the option to continue pressing with Tetrises or a laser item would already be particularly devastating.
Baiting
If your opponent is good enough to screen read, you can mess with them by defying their expectations. For example, you can choreograph a buildup to a Tetris hole on the right, only to plug it and clear a double elsewhere on your screen.
Player 1 sees a Tetris or possibly some skim doubles coming, and has left a 2-wide open on the right to counter.
Player 2 goes out of their way to mix up to the center columns.
Player 1 was not expecting the center garbage.
Baited, outsmarted, and outplayed, Player 1's double sends impotent garbage that Player 2 is already well positioned to handle.
