Damage
Damage is dealt through normal attacks by breaking panels, in which case it's calculated based on the attacking unit's attack stat, and by skills, in which case the calculation is either based on attack or is a specific power. Units always deal damage of their attribute unless one of their skills specifically deals damage of a different one. Enemy units can deal non-attributed damage.
Example of an attack-based skill:
1体にダメージ(威力:攻撃力×150％)
Damage to 1 unit (power: attack × 150%)
Example of a skill with a set power:
1体にダメージ(威力:27000)
Damage to 1 unit (power: 27000)
For both your units and for enemies, damage is increased or decreased based on a rock-paper-scissors-like system. Red is strong against green, which is strong against yellow, which is strong against blue, which is strong against red. 50% more damage is dealt to attributes a unit is strong against, and 50% less damage is dealt to attributes a unit is weak to.
Damage received is also decreased by a unit's defense, to a minimum of 1. Damage absorbed by a barrier (バリア) is negated entirely, including any excess damage from the hit that breaks the barrier. A unit might also have an effect in one of their skills or abilities that reduces damage by a specific percentage. Enemy units can also raise their defense and use damage reduction skills.
The counter (カウンター) effect causes a unit, when hit, to deal damage back to their attacker. Enemy units can also use counter.
Special panels
Crash panels (CPs) and special crash panels (SCPs) are formed at the end of the chain when you match a certain number of panels in a single tap. CPs are formed with 6–11 panels, and SCPs are formed with 12 or more.
When a crash panel is broken, it deals damage and/or has an additional effect based on the associated unit's crash skill. SCPs have the same effect, except they also explode when you break them.
Color break panels (CBPs) are color panels that, when broken, break all panels onscreen of the same color, including gimmick panels like damage panels.
Bombs (ボム) break the surrounding panels when they explode. The size of bombs left by SCPs depends on how many panels were chained to create it.
Magnets (マグネット) are color panels that can't be broken, but draw panels of the same color toward themselves. Magnets last for a limited number of turns and disappear once they expire.
Misc. effects
Incite (インサイト) is an effect a unit can trigger on themself. It causes enemies to attack that unit instead of other members of your party.
Multiple units can be under the effect of incite only if it's triggered by an ability. If multiple units incite the enemy at once, the attacks will be alternated between them.
Note that incite doesn't affect whole-party attacks.
There is at least one instance of a boss ignoring incite: Predation seems to ignore virus-immune inciting units in order to attack units that are infected with virus instead. I don't know if this is a bug or if it's intentional. (Details)
Chains (チェイン) allow you to chain together panels that aren't the same color, including gimmick panels. There are two types: accel chain (アクセルチェイン), which is from a specific panel to another, and multi-chain (マルチチェイン), which is from any panel to another.
Example of an accel chain (attribute to attribute):
赤色から緑色パネルのアクセルチェイン効果付与
Grants red to green panel accel chainMeaning: Tapping a red panel will cause it to connect with nearby green panels, but not the other way around.
Example of a multi-chain (attribute to attribute):
黄色のマルチチェイン付与
Grants yellow multi-chainMeaning: Tapping any panel will cause it to connect with nearby yellow panels.
Example of a multi-chain (attribute to gimmick):
ダメージ・赤・緑色パネルのマルチチェイン効果付与
Grants damage, red, and green panel multi-chainMeaning: Tapping any panel will cause it to connect with nearby damage panels of any color, red panels, and green panels.
Lasers (レーザー) are beams that shoot across the screen and break whatever panels they hit, including gimmick panels regardless of a unit's abilities. There are some exceptions, like charge panels and panels behind a dimension shield.
Charge panels (チャージパネル) are large color panels that are placed in a specific area, where they remain stationary. They can last for a limited number of turns or be permanent. Charging them up by chaining them triggers their effect.
Charge panels aren't affected by lasers, but they are removed by fever.
Enemies can also place charge panels that may have negative effects.
Example of an effect that places a charge panel:
3ターン中央にブルーチャージパネルⅢ(X型に大レーザー)を配置
For 3 turns, put a blue charge panel III* (large X-shaped laser) in the center
*The roman numerals denote the number of times the panel has to be charged for its effect to trigger.