In the Pikmin series, Pikmin and leaders need to engage in combat against the many different enemies they encounter. Combat is a core mechanic of the series, as it is frequently required to open up paths or retrieve collectibles. There are many ways of damaging enemies and many technicalities of the combat system. To defeat an enemy, its health must be reduced to 0.
The main way Pikmin damage enemies is by slapping them with their stem. Unless thrown directly onto an enemy, a Pikmin will stand next to them, periodically jumping at the enemy to smack them with their stem. There is also the possibility of them eventually latching on and dealing damage at a much faster rate. Some enemies, like Female Sheargrubs, are far too small to be latched onto but have a small enough health pool that they die quickly. Other enemies, like the Anode Beetle, are larger but still cannot be latched onto. Idle Pikmin will automatically begin hitting nearby enemies, obstacles, and eggs. In Pikmin and Pikmin 2, swarming an enemy will cause most of the involved Pikmin to latch onto it, if possible, and begin attacking. In Pikmin 3, Pikmin that are charged into an enemy will always immediately latch onto it if they make contact with it. However, Pikmin will still be unable to latch onto enemies that aren't much larger than they are.
In competitive modes like 2-Player Battle in Pikmin 2 and Bingo Battle in Pikmin 3, Pikmin can be commanded to harm other leaders or their Pikmin. This can be accomplished by throwing, swarming, or charging Pikmin into another player's leader or forces, although in 2-Player Battle, Pikmin merely need to be standing by the opposing leader or their Pikmin to initiate combat. In Pikmin, Mushroom Pikmin can also attack Captain Olimar and his Pikmin in a similar fashion.
Each Pikmin will attack with a constant rhythm, and as a result, having more Pikmin on an enemy increases the rate of damage. Different Pikmin types deal different amounts of damage per slap hit in different games, as shown in the following table:
Purple Pikmin pound
In Pikmin 2, when a Purple Pikmin is thrown onto an enemy, it will pound onto that enemy from above, dealing much more damage than a standard hit. The exact damage depends on the enemy. Each pound also has a chance of stunning an enemy; the duration of the stun also depends on the enemy.
White Pikmin poison
When a White Pikmin is eaten by an enemy, that enemy will instantly take damage from the White Pikmin's poison. The amount depends on the enemy and the game.
Rock Pikmin throw
When Rock Pikmin are thrown directly at an enemy, instead of latching on and hitting it, they will bounce off it like a rock, dealing a high amount of damage. This damage varies by enemy, as every enemy has an internal value for the number of Rock Pikmin impacts it takes to defeat it. For example, a Bulborb has 1000 HP and takes 25 Rock Pikmin hits to kill, so each hit does 40 damage, whereas a Medusal Slurker has 750 HP and takes 10 Rock Pikmin hits to kill, so each hit does 75. Their damage when thrown is also different from when they are charged, and the exact damage caused depends on circumstances and game.
When a leader doesn't have any Pikmin in their squad, they can perform a punch, or in the case of Pikmin 2 with the Rocket Fist, a series of punches. The exact damage depends on the game and the type of punch.
Bomb rocks can be used in combat. Their explosions deal a variable amount of damage to objects in range, though they usually cause much more damage to an enemy that ingests it directly.
It's usually a good idea to pile as many Pikmin at once onto an enemy, maximizing the damage done to it as well as causing it to focus more on shaking off its attackers rather than eating them. That said, depending on the enemy, it may be even more advantageous to wait until the enemy is vulnerable before rushing. If an enemy is busy in the middle of an idle action that cannot be interrupted, like a Bearded Amprat stretching, that is a great opportunity to strike, since it buys the player more time before the beast counter-attacks. Enemies can also be coaxed into performing long, relatively safe actions using one or two Pikmin, like a Fiery Blowhog being enticed to buck Pikmin due to one or two Pikmin; since after this, it follows up with a flame-spitting attack, this gives a lot of time to attack its back while it cannot do anything to the Pikmin.
Some enemies have weakspots, can only be attacked at a certain part of their body, or can only be attacked in a special way. Bulborbs in Pikmin 3 can have Pikmin thrown at their eyes, which causes them flinch. The Toady Bloyster in Pikmin 2 is most usually attacked at its bulbous tail, but Purple Pikmin can pound its main body to cause damage. Some enemies, such as the Quaggled Mireclops, are only vulnerable at certain parts of its body: in this case, the creature's fleshy hooves and fruit-like head are the only vulnerable parts. Breadbugs and their larger counterpart cannot be swarmed, but Pikmin can be thrown onto their back to inflict damage. Smaller enemies such as dwarf bulborbs and most mandiblards can be killed instantly by throwing a single Pikmin onto its back.
Although Pikmin that are captured by an enemy will quickly be swallowed and killed, they may be able to be saved. By killing an enemy with Pikmin in its grasp before it can swallow them, the Pikmin will be released safely. In Pikmin 2, enemies can also be petrified with a dose of ultra-bitter spray to prevent them from eating any Pikmin they may have in their mouth, buying precious time for the player to finish the creature off. Some enemies may also forcefully spit out Pikmin that haven't been swallowed yet when attacked in a certain way, like if a Pikmin is thrown at a bulborb's eyes in Pikmin 3.
Leaders and Pikmin, too, can be damaged during combat. As with Pikmin, leaders can be bitten, knocked back, crushed, and suffer negative consequences for touching a harmful hazard. Leaders can collect upgrades, which can help protect them from damage. On top of losing health, leaders can also suffer other consequences from attacks, as elaborated here.
Pikmin do not seem to have health that can be depleted, although this is hard to confirm, as explained here. During combat they can still be harmed. In Pikmin and Pikmin 2, Pikmin that are knocked down by an enemy have a chance of their maturities being reduced as explained here. In Pikmin 3, Pikmin that are shaken off of an enemy or fall off of one will retain their maturities. In any Pikmin game, Pikmin that are shaken off of an enemy will briefly lie on the ground before getting up, but this is not always the case. Pikmin battling a Shaggy Long Legs that fall off one of its legs after picking the hairs off one of its joints will get up on their own, but Pikmin the creature shakes off normally will remain on the ground indefinitely until they are whistled, as bumping into them does nothing.
Flower-stage Pikmin that die in Pikmin have a chance of leaving behind a seed that becomes a sprout the following day and can be plucked. Hazards like fire, water, and poison will respectively cause all but Red Pikmin, Blue Pikmin, and White Pikmin to begin scrambling wildly with that corresponding hazard on the end of their stem. Enemies in Pikmin 2 that use electricity are arguably the deadliest, as electricity in that game can instantly kill Pikmin. Electricity in Pikmin 3, however, is harmless, only causing non-Yellow Pikmin that come in contact with it to be thrown back, onto the ground, paralyzed, until they are whistled.
Enemies have a variety of ways to harm or kill Pikmin, such as deflowering them, burying them, crushing them, eating them, or using another hazard against them. Most enemies have a limit on how many Pikmin they can kill or harm at once in a given attack. For example, a Spotty Bulborb in Pikmin can only gobble 3 Pikmin at most in a single chomp, but a Spotty Bulbear can capture up to 5. Some enemies can also harm other enemies or themselves; a prime example is the Decorated Cannon Beetle, a creature that spits boulders which can be led into other enemies or even the creature that launched it.