Lock-on is a combat and exploration mechanic added in Pikmin 3. This feature makes the camera lock on to and focus on a certain enemy, obstacle or other object. This allows players to not lose its sight, making attacking easier, as well as obtaining its name and allowing the Pikmin army to charge.
To lock-on, the player must move the cursor to an object. One can tell that it is possible to lock-on if the cursor changes from being a simple circle with a dot projected on the terrain, to a circle with three triangles pointing inward, facing the screen. The cursor will not change, nor will the lock-on activate, if the leader is too far away from the target. Afterwards, the player must press 
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for roughly one second to lock-on to the object. Although hardly useful, the cursor changes aspect to indicate how much more the player needs to hold the button down for, so that the lock takes place. Unlike other Nintendo games that have lock-on functionality (e.g. Metroid Prime), the player does not need to hold the button in order to keep the lock. Pressing the same button again cancels the lock-on.
Once locked-on, the camera zooms in and focuses on the object, and rotates to follow it around. The left and right portions of the screen also darken, two curved lines appear near the darkened areas, and some textual information is shown on some corners of the screen. The bottom-right corner contains the object's name, as well as some characters written in Koppai's language. The top-left corner shows an icon of the same button used to trigger lock-on, but with the string "Cancel Lock-On" afterwards: this indicates that the button can be pressed again to cancel. The bottom-right corner shows that issuing a dismiss in this state (
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/ ) makes the Pikmin party charge at it. With Stylus mode, this text doesn't exist, but instead, the dismiss button on-screen changes to the caption "Charge".
When locked on, the manual camera controls will not work. Dodging will make the leader and Pikmin roll around the object, as opposed to rolling in a straight line left or right.
Charge
By dismissing while locked-on, leaders can make their Pikmin charge at the object. This causes them to run in a hurry at the target and interact with it, much like they would if thrown at it. This effectively replaces the group move mechanic from the previous games. After activating the charge, a horn is heard, the Pikmin jump up and perform a battle cry, and after a small delay, they run at the object.
Nothing will happen if the player attempts to charge with no Pikmin or leader in their party. When charging, any leaders following the current leader will be dismissed. Pikmin not suited for the task will move slightly towards the target, but will retreat shortly after and rejoin the group. This happens for the following Pikmin:
- Flowered Pikmin directed towards nectar.
- Non-Winged Pikmin directed towards Bamboo Gates or Flukeweeds.
- Bomb Rock-wielding Pikmin directed towards anything.
Due to a glitch of sorts, at times, when Pikmin are told to charge at an object, they stop moving after around half a second and remain idle in place. The cause for this is currently unknown.
History
Prior to version 2.0.0, the pieces of text on the left corners of the screen didn't exist. They were added with the update, in order to make it easier for players to know how to cancel the lock-on and how to charge.