The character's powers or artificial life support systems/spells come with a finite Power Source or number of usages. Once that fuel meter runs out, either they can never use that power again, or they die.
Usually said doom is averted before it ever comes to that, but not always — a character may have to employ Heroic Willpower to push through, learn to function when you're depowered, or use their last bit of power to enact a Dying Moment of Awesome.
Compare Hour of Power, which is limited in period but can always be reused or recharged, and Cast from Lifespan, which uses a character's lifespan instead of some other sustaining power source (the two overlap in cases where lifespan is directly linked to their expression of this trope — say, a Powered Armor spacesuit with limited battery life, or a Pure Magic Being that can't easily regain mana). Compare also Power Degeneration, which often overlaps when Toxic Phlebotinum-type side effects set in or a character gets weaker as their batteries deplete. See also Justified Extra Lives, which may employ this trope as part of its explanation.
Compare and contrast Mana Meter, which can generally be refilled, so that you aren't permanently depowered when you used your power often enough (it just has to be refilled).
- .hack's data drain powers increase your viral corruption, although it is possible to lower it, overuse results in random chance of various effects (both positive and negative), eventually resulting in game over from viral takeover.
- Fairy Tail: Natsu gets this with post-second Time Skip with Igneel's remaining Magic Power within his body, which he can access to unleash the full power of Fire Dragon King Mode. Since the power in question can't be regenerated since Igneel is dead, Natsu can only use it to its fullest potential once, and while he can substitute his own Magic Power, the resulting transformation isn't nearly as impressive. Of course, nothing's stopping Natsu from naturally reaching that level of power on his own with enough time and training.
- All superheroes in Gamma are powered by the Lambda energy in their bodies. Once it runs dry, they lose whatever powers they had.
- Miroku from Inuyasha. The "wind tunnel" in his hand is almost story-breakingly powerful (it's basically a personal black hole), but will eventually grow powerful enough to consume him too (unless the demon who put it there is killed). It's constantly slowly expanding no matter what he does, but using it to inhale monsters accelerates the process. Injuries to that hand open it more, shaving off even more of his limited time.
- All Might of My Hero Academia gave away the source of his powers to main character, Izuku at the start of the story. He still has a portion of its energy within him, but it's finite without the source. Each time he uses his strength, he burns up a bit more of his supply. By the end of the first third of the series, All Might is forced to use up the last of it in battle and is left permanently powerless.
- In Puella Magi Madoka Magica, in the new universe created by Madoka in the final episode, magical girl power generally works like this. Instead of becoming a witch due to having your gem corrupted, when you run out of magical power, you simply fade away.
- In one issue of Infinity, Inc., Hourman II has exactly one hour of total time he can use to visit his father in an otherworldly realm.
- Nico Minoru's Staff of One in Runaways can cast any spell imaginable, but can't cast the same spell using the same incantation more than once. She finds several ways to work around this restriction, but they become more difficult each time she tries.
- Spawn has a necroplasm meter for some of his special powers. If he ever runs out of the stuff, he'll be sent back to Hell. He starts with a limited supply and goes through several recharges before eventually finding a way to remove the limitation.
- This is what makes Calvin's superpowers from the Calvin & Hobbes: The Series episode Super Calvin a Deadly Upgrade. They are fueled from his energy, and the process of getting them deactivated is a gene that allows him to regain that energy. Use of his powers drains his reserves very quickly, and once it's gone, he can't get it back.
- In Ruby Haze the Phantom Ruby has a finite amount of power and John needs to pull energy from other sources to recharge it. It also tends to burn through energy fast, so one of Johnís ongoing missions is to find a way to reliably charge it.
- In The Girl Who Leapt Through Time, the main character discovers a device that allows time travel. Unbeknownst to her there was a limited number of uses, and she used them up on trivial and inconsequential things, leaving her out of uses when she really needed it to save a life. Thankfully, a Deus ex Machina arrives with The Reveal.
- In Ghost Rider (2007), the previous Rider fades away after one last change.
- In Maburaho, all magic users can only use their powers a limited number of times. If they use up all their spells, they die and their bodies crumble to ash.
- In Worm, capes whose powers come from Eden/The Thinker's dead shards have a limited well of power to tap on, and some of such characters run out during the final battle.
- One of the Xanth books features as a key character a little girl who appears to have the talent to have all the talents, ever. Eventually the heroes notice a pattern, or specifically, a lack thereof; it turns out that the limitation (which every talent has) is that she can only use each talent once. After this, she gets much more conservative with it; before, she was kind of a spoiled brat because if things didn't go the way she wanted, she'd just magic them into something more to her liking, and not even her parents could do anything about it. To clarify, she has every magic talent possible; but she can use similar talents for the same effect. For example, she could make clean drinking water by cleansing it, distilling it, reversing time to when it was clean, transmuting it, etc. In another book, The Dastard, she finds out that the limitation is actually that each spell is on a years-long cooldown. Unfortunately, his talent allows him the ability of reversing a short period of time; and he caused her not to come to the realization. So far, she still doesn't know.
- In Kamen Rider Den-O, Zeronos must use up a Zeronos Card to transform, and he has a very limited number of them. At one point, he actually does run out and is unable to assist Den-O with the Monster of the Week. Later, he receives red Zeronos Cards, which are still finite and offer more power at the cost of memories from his past.
- Power Rangers/Super Sentai:
- Invoked twice with the Mighty Morphin Green Ranger, then again with the Lightspeed Rescue Titanium Ranger. In both cases, the Rangers originally had unlimited use of their power before the bad guys came and put a cap on it (and the Titanium Ranger was eventually able to remove his restriction).
- The Sentai that Mighty Morphin is based on, Kyōryū Sentai Zyuranger, has the same thing with their green ranger, which was actually what forced it to be used in Power Rangers due to stock footage constraints. Also notable, Zyuranger's green ranger is Killed Off for Real.
- Taken does this with a young alien boy who eventually burns himself out using his powers.
- Breath of Fire: Dragon Quarter has exactly this; the main character's draconic powers are limited by how long he can remain in his Super Mode state. When the meter is full, he dies. Game Over. No way to lower it, whatsoever. The game is designed with the expectation that you'll eventually overtax it and die — then you can start over from the beginning, keeping much of your character advancement and items and unlocking new cutscenes that reveal more of the story. Repeat until you can clear the game without going over.
- Dungeon Crawl's gods are fueled by worship. For most of the gods, this isn't a problem — Ignis, however, is a long-forgotten god that has all but entirely faded away. Instead of granting its single remaining follower (you, if you start as a Cinder Acolyte or somehow stumble across an exceedingly rare altar) divine powers that gradually recharge as you gain favor, it grants all the power it has left all at once. Followers of Ignis gain a few fiery abilities that are potent early on, but have no means of replenishing them; once you've burned through your piety, Ignis is reduced to a vestigial husk of a god that can do nothing more than partially protect you from fire.
- Emiya Shirou in Fate/stay night's Heaven's Feel scenario. He can use his Projection magic only 3 times after defeating Dark Berserker with Archer's arm. After that, best-case scenario he renders himself a brain-dead vegetable, and far more likely kills himself outright thanks to his body literally turning into swords and his mind burning out from the strain.
- All of your defenses in the original Five Nights at Freddy's drain your power (and it drains slowly even if you don't use anything because of the light and fan in your room). Once it's gone, your room will go dark and you'll probably be killed by Freddy unless the clock ticks over to 6 AM. This also applies to your flashlight in Five Nights at Freddy's 2. Use it too much and you won't be able to look down the hall to see what's coming after you — and you have no way to defend yourself against Foxy, who can only be deterred by flashing your light at him.
- Grief Syndrome uses this for its Soul Limit feature. Each character has a Soul Limit stat that slowly drains over the course of the game, though some of your Soul Limit can be burned to regenerate health and even bring yourself back from the dead. Once it reaches zero, that character is Deader than Dead and unavailable for the rest of the game.
- The Lightning in MediEvil can't be recharged in either game and is the only weapon with no way to restock. This was rectified in the PSP Updated Re-release the first game — now the Lightning is just prohibitively expensive to recharge.
- A meta example from Metal Slug: Grenades deal a lot more damage than any of your other weapons, but you only start with 10, so it's a common strategy against bosses to use up all your grenades and apply More Dakka without trying to dodge, as getting killed replenishes your grenades and ends the boss fight faster.
- StarCraft's Spider Mines were limited to three per Vulture bike; StarCraft II: Wings of Liberty's campaign has an upgrade that lets you buy more when the stock is used up.
- In Warcraft III, some unit abilities like the Mortar Team's Flare and the Huntress' Sentry are limited to one per unit. The expansion makes it reusable after a long cooldown.