Cave

Caves are underground locations in  and. Exploring them is important since they contain treasures, castaways, Flarlic, and wild Pikmin inside. Each cave consists of a series of cramped sublevels that limit the player's possibilities, with the gameplay and ambiance inside reflecting that fact:
 * There are usually only one or two possible paths the player can follow to explore a given sublevel.
 * Since there is no access to Onions, it is impossible to retrieve more Pikmin, and getting new Pikmin can only be done with Candypop Buds, Bulbmin, or wild Pikmin.
 * The current day cannot be ended until the cave is exited.
 * The music in caves is significantly more minimal than the music in outside areas, and in Pikmin 2 is partially randomly generated following specific parameters, like the terrain.

Caves in both games are composed differently, with sublevels in Pikmin 2 being generated randomly each time, but following a specific layout scheme, while sublevels in Pikmin 4 are fixed and focus more on puzzle-solving. The two games also have other minute differences in the way caves work.

Caves are entered through holes in the areas. Similarly, somewhere in the cave is a way to exit it, allowing the player to safely return to the surface with all of their collected objects.

In Pikmin 2, stages in Challenge Mode and 2-Player Battle also take place in caves, but this article focuses on the caves in Story Mode, which includes Dandori Challenge and Dandori Battle stages. The other do not have caves per se, but have underground locations regardless. has The Forest Navel, has underground sections within its main areas, and  has some cave-themed levels.

Sublevel
Each cave is divided into a number of sublevels. Each sublevel consists of a small isolated location, and will usually have at least one treasure or castaway and a few enemies. The player can only play on one sublevel at a time, and there can't be any Pikmin activity outside the current sublevel or cave. The shortest cave in Pikmin 2 – Emergence Cave – has two sublevels and the longest – Hole of Heroes – has fifteen.

When a cave is entered, the player will land in its first sublevel, and will be able to proceed through that cave's sublevels in order through the use of holes. Some sublevels have a way to exit safely while keeping all collected objects.

Every time a sublevel is entered the game is saved, so if the player turns the game off and then back on again, they will start in the same sublevel. In the case of Pikmin 2, the sublevel will be generated randomly again.

While sublevels in Pikmin 2 are fairly generic, they can be roughly categorized into three types:


 * Normal levels usually have a few harmful enemies, and sometimes don't have any treasure.
 * Rest levels either lack enemies or only have harmless enemies (exceptions being Doodlebugs and Bulbmin). Rest levels have Pikmin-supporting items, such as nectar, ultra-bitter spray, ultra-spicy spray, or Candypop Buds. These levels usually lack treasures, and feature special ambient music. Most rest levels also have a geyser available, so the player can return to the surface if they have a low number of Pikmin.
 * Boss levels contain one or more large bosses, are usually the final level of a cave. The only cave without a boss level is the Emergence Cave, and the one with the most is the Hole of Heroes. When the boss is defeated, it often drops an upgrade for the leaders' space suits or ship.

In Pikmin 4, sublevels are also simplistic for the most part, but their layout and objects are placed with purpose as to provide the players with a curated challenge, usually in the form of a puzzle or some tricky exploration. Some bits of the layout are references to or outright reworkings of cave units originally from Pikmin 2, such as  and.

Final floor
Since at the final sublevel of a cave there is nowhere else to go, all final floors contain a geyser or air vent for the player to return to the surface and end their cave mission.

Typically, final sublevels have something grand to them. In Pikmin 2, the final floor of all caves except the Emergence Cave is a boss level, and in Pikmin 4, most caves have a castaway to rescue at the final sublevel.

In Pikmin 2, the deepest sublevel of every cave receives special attention by the game and is known as the final floor, or the final level in the European region of the New Play Control! version. As the player drops into it, the game announces this by playing a distinct jingle, along with displaying the words "FINAL FLOOR!" or "FINAL LEVEL!" in large, yellow letters, before the player regains control. Additionally, on the HUD, the word "SUBLEVEL" in the top-right corner is replaced with the words "FINAL FLOOR" or "FINAL LEVEL" in yellow.

In Pikmin 4, there is far less attention drawn, simply displaying "FINAL SUBLEVEL" in place of the number as it fades away. For caves with only 1 sublevel (Burrow of Beginnings, Last-Frost Cavern, Dream Home), the distinction does not appear at all.

Hole
To enter a cave, the player must get close to a hole and press the throw button. To go from one sublevel to the next, the same must be done to a similar hole within the sublevel.

In Pikmin 2, the holes are round, rocky mounds, with a small hole in them. On the cave entrance hole, if the cave has not been completed, wisps of steam will come out, and the screen will become foggy when the hole is approached. In contrast, if it has been completed, a simple red flag will be placed near the entrance. Inside a cave, the hole to a next sublevel will always contain steam, but will not fog the screen.

In Pikmin 4, the holes are black tubes with colored lids – cyan for normal caves, gray for Dandori Challenges, and orange for Dandori Battles. They are actually Japanese, which are plastic tubes that house valves. After completing that cave, a flag appears in the color of the player's spacesuit with the Rescue Corps logo. When completing Burrow of Beginnings for the first time, Collin can be seen placing one such flag down in a cutscene. In addition, some caves have multiple holes, where the player will enter in one side and exit on the other such as the Aquiferous Summit and the Engulfed Castle. Entering the "exit" side of the cave from the surface will slightly change the layout to allow the sublevels to be cleared in reverse order, with an air vent that takes the player back to the "entrance" hole on the first sublevel. Exiting a cave from the pause menu will take the player back to the hole they entered from.

Passage of time
In Pikmin 2, the time of day does not pass while the player is in a cave. According to earlier versions of the game, this is because the space-time continuum was warped due to the cave's geomagnetic radiation field. The final version's instruction manual simplifies this and simply calls it "a powerful magnetic field".

In Pikmin 4, time does pass while underground, but only at a sixth of its normal speed. If the overworld time reaches the sunset countdown while the player is exploring a cave, nothing will happen and the player will be free to continue inside the cave for as long as they want, but as soon as they leave the cave the sunset countdown will begin. Caves also cannot be entered during the sunset countdown.

Object spawning
Some objects respawn between visits to the same cave, including enemies. The rules are as follows:

Treasures will not reappear once collected, unless the way the player exits the cave puts them back. Some Candypop Buds that have a maximum Pikmin requirement will also not show up.

In Pikmin 4, wild Pikmin, enemy corpses, treasures, and so on will remain in the same state the player left the cave in for a few days, position included, until the cave is completed, at which point the standard rules for respawning everything from scratch described above apply.

Entering caves
Once the player chooses to enter a cave from a hole, a confirmation menu appears with some information about the cave. In Pikmin 2 it shows the kinds of hazards inside, and in Pikmin 4 the first page lets the player pick a sublevel to land on from previously visited sublevels, and the second page shows the Onion menu so the player can pick which Pikmin join them inside.

If the player accepts, the current leader, the other leader or Oatchi, and the squad of Pikmin will all jump inside in a brief cutscene. For Dandori Challenge and Dandori Battle caves, the Pikmin will refuse to go inside, however. The other leader or Oatchi will join in regardless of distance, and in Pikmin 4, the player's character and Oatchi will also join in even if they are knocked out, despite the entering cutscene not showing it.

When entering a cave, any Pikmin that do not go in will be safely returned to their Onions. In Pikmin 2, Pikmin in an idle leader's group will not be a part of the Pikmin that go in, even if the idle leader enters.

Any leader and Oatchi will regain full health when entering a cave. In Pikmin 2, it is impossible to explore a cave without Pikmin, and while it is possible in Pikmin 4, the game shows a confirmation dialog stating that it's hard to explore without any.

Entering sublevels
To go to the next sublevel in the cave, the player must find a hole similar to the one used to get in the cave in the first place.

Unlike entering a cave, leaders and Oatchi will not regain any health when a deeper sublevel is entered. In Pikmin 4 certain sublevels will force Oatchi to fall in a spot far away from the rest of the crew, which usually results in the player having to solve some problem in the sublevel to reunite everyone.

Exiting sublevels
When the player chooses to exit the current sublevel, all non-sprout Pikmin, all conscious leaders, and Oatchi will automatically join the group and jump together, regardless of distance.

As explained below, when a sublevel is exited, if there are any unplucked sprouts, the game will notify the player about this and ask them if they wish to continue. The same happens if there are any uncollected Onions, Flarlic, or castaways.

Exiting caves
Like when entering a cave, the process of exiting a cave in any way restores the health of any leader or Oatchi, unless otherwise specified.

Safe exit
The standard way of exiting a cave is by finding a geyser in Pikmin 2 or an air vent in Pikmin 4. Either one will shoot leaders, Oatchi, and Pikmin back up to the surface. In Pikmin 2, the player is returned to the landing site while in Pikmin 4 they come out from a hole – usually the hole they went in from, but some caves have a different hole from which they are exited.

Failure
If the player is no longer able to explore due to a serious problem, the expedition will be cancelled, collected treasures will be lost in the process, and then any leaders or Oatchi will be brought to the overworld, a process which leaves the Pikmin behind if any were alive. In Pikmin 4, the game gives the player the option to rewind time instead of letting this happen. A cave's exploration can be cancelled for the following reasons:
 * In Pikmin 2, both leaders lose all their health. This also results in the day ending immediately afterwards.
 * In Pikmin 2, the player loses all Pikmin.
 * In Pikmin 4, the player's character and Oatchi lose all their health.

Losing all Pikmin (or all Pikmin of a single type) in Pikmin 4 simply results in a cutscene, a reminder to rewind time, and the possibility of continuing exploration regardless.

Manual abortion
In either game, a cave expedition can also be aborted manually in a controlled manner by using the pause menu. This will result in the leaders, Oatchi, and the Pikmin to hop inside the research pod or the S.S. Beagle and fly out. Doing this in Pikmin 2 will result in the treasures being left behind, but not in Pikmin 4.

Pikmin management
In Pikmin 2, the Pikmin limit is respected even inside caves, while in Pikmin 4 the player can have as many Pikmin as they want inside the cave, and even from more than 3 types, though the Pikmin they can bring in from the surface must still respect those two limits. Also in Pikmin 4, if the cave is exited with surplus Pikmin, any extras will simply be brought to the Onion when the player chooses what Pikmin types to take with them once they land.

If any Pikmin happen to be currently buried, attempting to leave a sublevel will prompt the game to warn you about abandoning the sprouts, showing a confirmation dialogue. What happens when a sprout is left behind a sprout works differently in the two games: While sprouts left behind are permanently lost in both games, they are only considered to be actual deaths in Pikmin 2; in Pikmin 4, they will not be considered as casualties in the Status Report screen.

Completion
As mentioned above, caves that are completed will have a small flag right next to their entrance.

In Pikmin 2, a cave is considered "complete" if all treasures within it have been collected.

In Pikmin 4, a cave is considered "complete" if all treasures and castaways within it have been collected. A completed cave's icon on the radar will show a hole with the lid open and a small golden flag next to it, while uncompleted caves show a closed lid.

Cave entrance leader mixup
When entering the first sublevel of a cave in Pikmin 2, the game may or may not switch the player's active leader. This does not happen when the player goes from one sublevel to the next, making it mysterious as to why the leader changes seemingly randomly when going to the first sublevel.

In reality, this happens because of a simple glitch. In order to decide what leader to turn active whenever a sublevel is entered (be it the first or not), the game reads a variable in memory. This variable is also saved onto the save game data and loaded from it. It is set whenever the player goes from one sublevel to the next, which explains why, when the next sublevel is loaded, the game selects the correct leader. However, this variable never gets set when the cave itself is entered. This means that when the first sublevel is finished loading, the game reads the variable, and uses an outdated value, last updated when a sublevel hole was entered. This glitch was not fixed for the New Play Control! or Nintendo Switch rerelease.

It can also be noted that Challenge Mode uses a different behavior, without a glitch, and that the default value of the variable is 0, meaning that at the start of the game, before the player goes from one sublevel to the next, the game will make Olimar the active leader when entering a cave.

Hole entrance grunt mixup
When entering a cave or sublevel hole in Pikmin 2, each leader grunts as he jumps. However, the first leader to jump will always make Olimar's sound effect, and the one behind will always make Louie's, regardless of the existing leaders and their order. The only exception is if the second leader is fallen, at which point only the first leader will grunt, still with Olimar's voice.

Pikmin 2

 * Cave hole glitch: It is possible for a leader to end up inside the cave hole's geometry, if he's placed on the hole's spawning point before it spawns.
 * Cave death count glitch: If a Pikmin is suffering from a hazard and the player chooses to go to the next sublevel, the Pikmin will still have the suffering animation when jumping down the hole. If they made that last cry, they will nevertheless be alive on the next sublevel, but the total Pikmin lost count will increase.
 * Fake Pikmin extinction: By entering a cave and dismissing at the same time, the game will let the player enter the cave with no Pikmin. It then instantly announces a Pikmin extinction.
 * There is a glitch that can happen when proceeding to the next sublevel. In the animation where everybody jumps into the hole, some Pikmin may appear idle and won't jump in. Thankfully, these Pikmin that don't jump in will appear on the next sublevel.

Trivia

 * Leaving a cave will always make the game switch to Captain Olimar, regardless of whatever leader the player had active before leaving.
 * In an earlier version of Pikmin 2, the player could leave caves with half of the collected treasure if they leave through the pause menu. However, all Pikmin would be lost in doing so.
 * The fanfare that plays when jumping into the first sublevel of a cave is played again on organ during the fanfare that plays when a deeper sublevel is entered.
 * On the Subterranean Complex's third sublevel, and possibly similar levels too, it is possible for the sublevel's hole to spawn on the zigzagging path instead of dead end or somewhere in the open. Since this place is so tight, it spawns a bit on the edge, and makes it possible for leaders or Pikmin to climb up the hole's mound and fall off the stage.
 * All story mode caves in Pikmin 2, besides the caves in the Wistful Wild, have some hint of some part of their contents as background scenery nearby. Examples of this would be the concrete block near the Citadel of Spiders (hinting towards the concrete theme), the ceramic tiling near the Frontier Cavern (hinting towards the brick wall designs) and the Shower Room being enclosed in a tiled tub (hinting towards the tile theme used in said cave).
 * In "dirt"-styled sublevels, it is possible to see buried treasure through the floor, in some angles.