History Main / OxygenMeter

** Averted in some levels, where Sonic displays SuperDrowningSkills, dying if he so much as touches the rippling water at the very bottom of the game world (if you're lucky, he may only lose rings, and bounce back onto land). On others, water is a relatively benign substance, merely reducing your running speed and jump height (swimming is out of the question), and in ''some'' cases (where it takes up a significant portion or even all of the level) requiring you to find air to breathe. Worse, there are even some places where the two are mixed; go too deep on, say, the (UsefulNotes/GameGear, Sonic 1) Jungle zone or the Aquatic boss fight, and you'll instantly pop your clogs.

* In ''VideoGame/MegaManBattleNetwork 5'', there is a water dungeon which you have to guide your current Navi through. While they are underwater, they are perfectly fine until they run out of "cyber-air" (really?), at which point their HP starts dropping rapidly until you either hit a cyber-air pocket or exit the water. Oh, [[FakeDifficulty and there's random encounters the whole way, including while you're attempting to fight the currents that push you back and drain your air, and while you're trying to avoid the whirlpools that drain your air.]] There's also three areas of this, each one progressively more frustrating. This is one instance Capcom cut something out of the English release for a good reason -- in the Japanese version, there were four areas. By the DS version, it was back up to four.

Somewhere in between SuperDrowningSkills and SuperNotDrowningSkills lies the Oxygen Meter, which indicates the PlayerCharacter's capacity to hold their breath. If the Oxygen Meter depletes, one of two things will happen: instant death by asphyxiation, or the player character's actual [[LifeMeter health]] will begin to drain.

* An example without water: ''LEGO VideoGame/RockRaiders'' had a meter measuring the remaining oxygen in the various caverns. Some levels had infinite oxygen, but in others it would be gradually consumed by your Rock Raiders. In those levels, building at least one Support Station is critical[[note]]also the victory condition in one level[[/note]], as it provides enough oxygen for up to nine miners to work worry-free.

* ''VideoGame/KirbyMassAttack'' is one of the few games in the ''VideoGame/{{Kirby}}'' series which has this meter.[[note]]And one of the only games to not feature Kirby in scuba gear when underwater.[[/note]] This meter is shared by all the Kirbys and the more Kirbys the player has, the bigger the meter is.
* The first ''VideoGame/{{Rayman}}'' game has SuperDrowningSkills, the second has an Oxygen Meter which can be refilled by collecting blue lums, and the third lets you breathe underwater indefinitely.

* ''VideoGame/OriAndTheBlindForest'' has an oxygen bar that lasts for roughly 15 seconds before Ori's health begins to drain. Strangely, drowning in this game is the only way to die that doesn't employ CriticalExistenceFailure (Ori clutches at their throat and visibly inhales a lungful of water upon death, rather than exploding into a shower of magic sparks as usual), and can be averted entirely via an upgrade that ditches the meter for SuperNotDrowningSkills.

* In ''VideoGame/BanjoKazooie'', when the Oxygen Meter runs out, you immediately drown. [[ThatOneLevel Rusty Bucket Bay]] has oily water that not only drains the meter twice as fast when submerged, but drains it at the regular speed ''when on the surface''. This is rectified slightly in ''Banjo-Tooie'', where once the Oxygen Meter goes, your health starts to go down really quickly instead (this is also the case for areas where oxygen is depleted due to toxic airs or very naughty smells).

* In the {{Water Level}}s of ''VideoGame/AssassinsCreedIVBlackFlag'', Edward will slowly run out of air, shown on a meter. He can replenish his air by sticking his head in various pockets of air contained in overturned barrels or underwater caverns, or by simply returning to the diving bell used to reach the sea floor.

* ''VideoGame/ConkersBadFurDay'' has one of these once you're able to swim underwater (namely after consuming some pills in the Poo Cabin). When you're underwater, Conker's face and a stream of bubbles represents your air. As your air runs down, the stream of bubbles grows shorter, and Conker's expression becomes increasingly desperate. And his face starts turning blue as well. When his head droops, your chocolate bar (i.e., your health) starts falling apart rapidly. All six pieces go in about five seconds, so unless you're near the surface anyhow, you run out of air and die.

** Two-dimensional games give the PlayerCharacter an invisible oxygen meter, with a countdown from 5 to 0 followed by automatic death when it runs out. The indication of how much time remains is based on a [[NightmareFuel infamously-chilling]] [[SongsInTheKeyOfPanic background music]] that gradually speeds up as the timer reaches zero.

* DoujinSoft developer Creator/FoxEye takes this UpToEleven by having this mechanic in every last one of their games. This is mainly out of [[AuthorAppeal its lead designer's huge fascination with underwater exploration and the risk of drowning thereof]], essentially making this trope the developer's [[SignatureStyle modus operandi]]. Even in games where the Oxygen Meter isn't present (and several games where it is), the developer puts great care in showing that it still plays a significant role [[TruthInTelevision through the character's increasingly-distressing body language as they're running out of air]].

** ''VideoGame/HadesVanquish'' has one that is {{cap}}ped by Mana's LifeMeter. So how long she can hold her breath underwater depends on how much damage she took beforehand. If Mana has no items to recover her health or revive her after death, FailureIsTheOnlyOption if you're forced to take a dive with little health left, which has her drown in only [[SuperDrowningSkills a few seconds]].

* DoujinSoft developer Creator/FoxEye takes this UpToEleven by having this mechanic in every last one of their games. This is mainly out of [[AuthorAppeal its lead designer's huge fascination with underwater exploration and the risk of drowning thereof]], essentially making this trope the developer's [[SignatureStyle modus operandi]]. Even in games where the Oxygen Meter isn't present (and several games where it is), the developer puts great care in showing that it still plays a significant role [[TruthInTelevision through the character's increasingly-distressing body language]].

* DoujinSoft developer Creator/FoxEye takes this UpToEleven by having this mechanic in every last one of their games. This is mainly out of [[AuthorAppeal its lead designer's huge fascination with underwater exploration and the risk of drowning thereof]], essentially making this trope the developer's [[SignatureStyle modus operandi]].

[[quoteright:350:[[VideoGame/SuperMarioGalaxy https://static.tvtropes.org/pmwiki/pub/images/mariooxygenmeter.png]]]]

[[quoteright:300:[[VideoGame/SuperMarioGalaxy https://static.tvtropes.org/pmwiki/pub/images/mario_airmeter.jpg]]]]

Frustratingly, your oxygen meter is sometimes invisible yet still just as real and waiting to bite you; this is most likely to happen in a first person shooter. This is probably just because the interface is already full and they don't want to waste space on something not even used in most levels... and surprisingly, not all games decided to only make it visible when in use.

[[folder:First Person Shooter]]
%%* Many ''Franchise/JamesBond'' first person shooters.

* ''VideoGame/CaveStory'' has an oxygen meter which appears when the protagonist is underwater. Curly carries an oxygen tank which lets survive underwater indefinitely, which she gives to the protagonist at one point.

[[folder:Third Person Shooter]]

A third way, of course, is to just prohibit underwater travel entirely--either by limiting swimming mechanics to the water's surface (such as in ''VideoGame/{{Bully}}''), using SuperDrowningSkills, or by simply not allowing the player to interact with deep water in the first place using [[InvisibleWall Invisible Walls]]. (Sure, you can still splash around in puddles and knee-high streams, but to go jump in a ''lake''? Are you crazy?)

* ''VideoGame/HorizonZeroDawn'' has one for when Aloy dives underwater whilst stealth-swimming; this makes it easier for her to sneak up on enemies in or near the water and harder for her to be detected. However, if she stays under for more than approximately 30 seconds, Aloy begins to drown and she flails whilst making pained groaning and choking noises -- her health decreasing rapidly until she either re-surfaces or suffocates. Of course, she can use any health-granting items on her person to survive longer, but it does raise the question of [[FridgeLogic how she's able to eat whilst holding her breath]].

* The ''VideoGame/{{Thief}}'' games have an oxygen meter that looks like a line of bubbles across the bottom of the screen. If you knock someone unconscious and dump him in water, he will die in about the same span of time you would (so don't dump unconscious guards in swimming pools if you're running a no-kill mission).
** Averted in ''VideoGame/ThiefDeadlyShadows'', where Garrett has learnt SuperDrowningSkills.

* While you don't get a visible oxygen meter in VideoGame/TeamFortress2, stay underwater too long and your character will begin to take damage and make choking noises as the screen tints blue round the edges with each "hit" taken, eventually dying in the same manner as an environmental hazard when their health runs out. As with the ''Half-Life'' and ''Quake'' series above, health lost from drowning is restored by coming up for air, but pauses if you go back underwater. Oddly enough, Medics and Dispensers can heal players faster than drowning can kill them, so they're sort of like oxygen masks or tubes.

* ''VideoGame/CaveStory'' has an oxygen meter which appears when the protagonist is underwater, although one might wonder why, since he's a robot. Players trying for the [[MultipleEndings secret ending]] will eventually discover while saving Curly that surface robots are programmed to shut down if their systems get flooded with water, but this leads one to ask how carrying an oxygen tank enables one to survive underwater indefinitely.

* The ''VideoGame/{{Rayman}}'' series plays with this a bit. The first game has SuperDrowningSkills, the second has an Oxygen Meter which can be refilled by collecting blue lums, and the third lets you breathe underwater indefinitely.

* In ''VideoGame/FTLFasterThanLight'', rooms on spaceship can have pressure from 0 to 1 atmosphere (shown as white at 100% pressure and getting redder as it drops) which can be replenished by a working life support system and depleted by opened airlocks, fires, hull breaches, hacked life support or the Lanius. If pressure falls below 5% (indicated by red diagonal stripes), organic beings staying there that aren't Lanius start rapidly losing health, but any fire there will get extinguished. Humorously, an upgraded medbay can restore health faster than underpressure depletes it.

* ''VideoGame/DistortedTravesty 3'' has a blue bar on the left side of the screen that appears whenever your head is below the water. Additionally when it's within five seconds of running out, [[https://youtu.be/xTkDI0cUj_4?t=1m28s big green numbers]] [[ShoutOut straight from]] ''Franchise/SonicTheHedgehog'' appear right above the player's head and start counting down.

* ''Franchise/SonicTheHedgehog'':

* In ''VideoGame/DeusEx'', your health would also start decreasing when you run out of oxygen and start gulping water. While there are [[InstantExpert skills]], items, and {{Upgrade Artifact}}s to increase the amount of time you can hold your breath, the powerful health regeneration Upgrade Artifacts and instant-use [[HealThyself medkits]] allow one to use HitPoints as an extra Oxygen Meter.

* In ''VideoGame/FTLFasterThanLight'', rooms on spaceship can have pressure from 0 to 1 atmosphere (white at 100% pressure and getting redder as it drops) which can be replenished by a working life support system and depleted by opened airlocks, fires, hull breaches, hacked life support or the Lanius. If pressure falls below 5% (indicated by red diagonal stripes), non-Lanius beings starting rapidly losing health and fire gets extinguished. Humorously, an upgraded medbay can restore health faster than underpressure depletes it.

* In level 3 of ''VideoGame/MDK2'', Dr. Hawkins is trapped in a large room with an open airlock that's sucking him towards it. The player has 10 seconds, shown on the screen, to find a way to stop [[ThrownOutTheAirlock getting sucked into space]] and then find a spacesuit ([[FishbowlHelmet or in this case a fishbowl]]) so he can breath.

* ''VideoGame/EccoTheDolphin''. {{Justified|Trope}} of course, since the whole game was set underwater and dolphins can hold their breath for quite a while. When the oxygen meter runs out, health begins to drain.

** Health lost to drowning being replenished by coming up and a line from the first game's tutorial sequence suggests that when you go underwater in the first game or the suit's auxiliary power runs out in the second, Gordon is merely holding his breath; when health starts dropping, it's a sign that he used up the air in his lungs and [[FridgeBrilliance what we see as his health actually represents his blood oxygen levels in this case]]. Just like in real life, staying underwater kills him because he holds his breath for so long he passes out from lack of oxygen - which is indirectly fatal when it happens underwater, especially if no one's around to pull a comatose scientist and his who-knows-how-heavy PoweredArmor out of the dip. Still doesn't explain how he [[SuperDrowningSkills runs out of air so quick]]; maybe the suit's weight makes him have to exert more force to move underwater, using up air faster than normal. On the other hand, he IS a [[SquishyWizard mere scientist, not a soldier or hobby swimmer]].
** ''VideoGame/HalfLife2'''s auxiliary power supplying him oxygen can be explained away by his suit using that electricity to electrolyse oxygen from the water as he swims. Once that runs out, it's back to good old lungs.

* ''VideoGame/KirbyMassAttack'' is one of the few games in the ''VideoGame/{{Kirby}}'' series which has this meter.[[note]]This could be justified, as this is one of the only games to not feature Kirby in scuba gear when underwater.[[/note]] This meter is shared by all the Kirbys and the more Kirbys the player has, the bigger the meter is.

** Health lost to drowning being replenished by coming up and a line from the first game's tutorial sequence suggests that when you go underwater in the first game or the suit's auxiliary power runs out in the second, Gordon is merely holding his breath; when health starts dropping, it's a sign that he used up the air in his lungs and [[FridgeBrilliance what we see as his health actually represents his blood oxygen levels in this case]]. Just like in real life, staying underwater kills him because he holds his breath for so long he passes out from lack of oxygen - [[CaptainObvious which is indirectly fatal when it happens underwater]], especially if no one's around to pull a comatose scientist and his who-knows-how-heavy PoweredArmor out of the dip. Still doesn't explain how he [[SuperDrowningSkills runs out of air so quick]]; maybe the suit's weight makes him have to exert more force to move underwater, using up air faster than normal. On the other hand, he IS a [[SquishyWizard mere scientist, not a soldier or hobby swimmer]].

* In level 3 of ''VideoGame/MDK2'', once you find a way to stop getting ThrownOutTheAirlock, you're given 10 seconds, shown on the screen, to find a way to stop choking to death due to underpressure.

* In the ''VideoGame/WiiPlayMotion'' minigame "Treasure Twirl", your diving suit-clad Mii has to dive into the sea to salvage the treasures that hide in it, but they have to get back up before they run out of oxygen. Thankfully, there are some conveniently-placed oxygen tanks underwater so you can slightly refill your oxygen meter during the dive.

* In the ''VideoGame/WiiPlayMotion'' minigame "Treasure Twirl", your scaphander-clad Mii has to dive into the sea to salvage the treasures that hide in it, but they have to get back up before they run out of oxygen. Thankfully, there are some conveniently-placed oxygen tanks underwater so you can slightly refill your oxygen meter during the dive.

* In the ''VideoGame/HalfLife'' series, your [[PoweredArmor hazardous environment suit]] provides you oxygen for a limited time. Oddly, the same meter that powers your sprint ability and flashlight is used for this in the second game. Once the suit runs out, Gordon has to start holding his breath. Once ''that'' runs out, your health starts dropping, but you can refill the health that you lost from drowning by coming up for air.

* ''VideoGame/SuperSmashBros Brawl'' has an invisible one just for swimming. Some characters (e.g. Squirtle) can swim longer than others (e.g. Charizard), but anyone will sink eventually. In the Subspace Emissary, some stickers can increase the length, but there really isn't any need for it.

* In ''VideoGame/FTLFasterThanLight'', rooms on spaceship can have pressure from 0 to 1 atmosphere which can be replenished by a working life support system and depleted by opened airlock, fires, hull breaches, hacked life support or the Lanius. If pressure falls below 5%, non-Lanius beings starting rapidly losing health and fire gets extinguished. Hilariously, an upgraded medbay can restore health faster than underpressure depletes it.

* In ''VideoGame/AnUntitledStory'', you even get upgrades that extend your oxygen meter.
* ''VideoGame/EndlessOcean'' essentially averts; it *does* have an oxygen meter for your air tanks, but it's a rather long one and most tasks get completed without running out of air ever being a factor. When it does run out, you get warped back to the boat. The sequel does tweak things a bit; dangerous fish attacking you knock your air out faster. Certain equipment upgrades up your air supply in both games.

** ''VideoGame/HadesVanquish'' has one that is [[{{Cap}} capped]] by Mana's LifeMeter. So how long she can hold her breath underwater depends on how much damage she took beforehand. If Mana has no items to recover her health or revive her after death, FailureIsTheOnlyOption if you're forced to take a dive with little health left, which has her drown in only [[SuperDrowningSkills a few seconds]].

* ''VideoGame/{{Minecraft}}'' gives you small air bubbles underwater. Once used up, you lose health over time, and originally began recoiling from damage, making it VERY hard to surface(this was eventually patched out). Helmets enchanted with the Respiration ability decreases oxygen consumption, including drowning damage.

* The ''[[VideoGame/{{X}} X-Universe]]'' gives you a two-hour air supply on your spacesuit, though checking it requires you to open up the spacesuit's info screen. Two hours is usually plenty of time for you to do whatever you need to, although it's possible to run out if you're trying to patch up a capital ship's hull with the suit's [[HealingShiv repair laser]]. Somewhat bizarrely, when your oxygen runs out, you explode.

* ''Videogame/EliteDangerous'''s starships have nigh-100% efficient closed circuit life support systems, but all that goes out the window if [[SnipingTheCockpit your cockpit canopy is shattered in combat]]. The oxygen vents out as your space suit automatically seals, and a ominous timer appears in the HUD indicating reserve oxygen levels. If you fail you enter a pressurized space station before the timer runs out, [[MadeOfExplodium kaboom]]. The backup life support can be upgraded from the base 5 minutes up to 20 minutes.

* ''VideoGame/MassEffect1'' features a variant; it lacks an actual ''oxygen'' meter, but many levels have environmental hazards in the form of extreme heat, cold, or gravitational pressure. The player is safe inside their vehicle, the Mako, but if they leave the vehicle, a meter will appear and slowly deplete. If it empties, the player dies, but the meter instantly fills back up if the player enters the Mako or a pressurized environment such as a building. Equipping certain types of armor that were noted as having been designed for use in hostile environments would slow or possibly even stop the meter from draining.

** This is the same case for the first ''VideoGame/SonicAdventure'' game, but in its sequel, two-thirds of the cast dies upon falling into water (save the small patch in the Chao Gardens). This eventually became the case for everyone over the course of the 3D series while the 2D games retained the classic countdown. Such is the case of the underwater Knuckles level "Aquatic Mine", which can be quite dangerous until you find the infinite oxygen item.