Someone Has to Die

"Spock: Do not grieve, Admiral. It is logical. The needs of the many... outweigh...

Kirk: The needs of the few.

Spock: Or the one."

- Star Trek II: The Wrath of Khan

This is a specific variation of the Heroic Sacrifice where because of a MacGuffin someone has to volunteer to die so that everyone else can live. This is taking one for the team ramped up to the ultimate sacrifice. The reason may involve Life Energy released upon their death.

In contrast to Taking the Bullet this is not a spur of the moment decision but one where the person making the sacrifice has time to think through a decision and usually give his Final Speech before making his sacrifice. Typically the speech includes the hero expressing that he knows exactly what he is doing and is willing to pay the price. Sometimes the hero even has to fight his own team for the right to die.

One of the most important aspects of this trope, it only works if the person volunteers. If anyone is ordered to be the sacrifice, then either someone's a villain or you're watching a dark comedy. Occasionally, a hero will volunteer and someone more expendable will stop them.

May, occasionally, diverge from a Heroic Sacrifice by way of Fridge Logic, in one specific situation: Everyone is doomed unless one character makes the sacrifice. However, only one character is capable of making the sacrifice, and unless he does, everybody (including him) is doomed. Usually, the story plays it as a Heroic Sacrifice anyway. Only later does the audience realize that, wait a minute--he didn't make a Heroic Sacrifice after all; he just decided he wasn't going to take everybody else with him when he inevitably kicked the bucket.

Closely related to You Shall Not Pass, but distinct in that there is no fight scene and death is certain. Sometimes it's justified by the person making the sacrifice having a Convenient Terminal Illness.

This is Older Than Feudalism, as it is the reason why Christ had to die in Christianity.

Anime & Manga

 * A variant of this trope happens in Tengen Toppa Gurren Lagann, when the team in trapped in the ocean of despair with two minutes 'till they all get crushed to death. At first Yoko tries to volunteer for the suicidal mission to destroy the Death Spiral Machine that maintains the Ocean, but before she can get the words out, Kittan volunteers, and shares a Last Kiss with Yoko, before going on to do his Crowning Moment of Awesome.
 * In Sonic X: Cosmo does this during the big series finale, requiring Tails to shoot the Sonic driver, which uses Sonic and Shadow as ammunition, into her while she is attached to Dark Oak in her adult tree form, thereby weakening him to a point at which he could be destroyed. Whether or not this was considered or Spur of the Moment is debatable, but it is said that this was supposed to have been her destiny all along. Cosmo, however, chooses to die not simply to fulfil her purpose, but because she wants to save her friends.
 * Higurashi No Naku Koro Ni Kai, in Matsuribayashi-hen. The villain is holding the heroes at gunpoint with only one bullet, and asks them to choose who will take the bullet to save everyone else. Subverted when Everybody Lives. "This world doesn't need a loser. That is the answer Furude Rika reached at the end of her thousand year journey in search of a miracle."
 * Penwood from Hellsing. As England is being obliterated by Milennium, he comes to the resolution (even though a little persuasion helps) to stay behind and fight to the end with the rest of his colleagues, just to take out however many vampires they can. With him soon being the only living person in the Hellsing residence, he holds a detonator in his hand and looks at a gun Integra gave him so that he could commit suicide. Choosing the more heroic option, Penwood waits until the vampires burst through a barricaded door, whereupon he adamantly answers their leader back in the face of death, and, even after being shot thrice, manages to detonate a huge stockpile of C4, taking the vampires and the entire Hellsing building with him.
 * In Robotech the Shadow Chronicles, Alex Romero flies his fighter with overloading Synchro-Cannon on board into a bunch of pursuing Shadowfighters. Later Markus throws escape capsule with Maya towads safety and stays behind(rather than call for help) to deter enemy fighters, though this borders with You Shall Not Pass situation.
 * In Sailor Moon S, Saturn uses her power to stop Pharaoh 90 even though it will kill her. Of course Sailor Moon saved her in the end.
 * One Piece, during the prison break out of Impel Down. Someone had to stay behind to make sure that the final obstacle, the Gates of Justice, would be open to let everyone else through to escape. Mr. 2 Bon Kurei volunteers for the role, using his Clone-Clone Fruit powers to pose as the prison's warden, and gets everyone out just as the real Warden confronts him.
 * The entire last half of the first Bleach movie focuses on this.
 * At the end of Farewell Space Battleship Yamato, Wildstar convinces the scant other surviving crewmembers - Venture, Homer, IQ-9 and some Redshirts - that they do not need to die with him in the final attack on the Comet Empire, and they leave on a medical shuttle. It's implied their spirits or wills to live died with him, however, as the final scene of the movie is Wildstar totally hallucinating orange images of all his friends, dead or alive, on the bridge.

Comic Books

 * Ferro Lad in the Legion of Super Heroes sacrificed himself to destroy the Sun-Eater. This happened in both in the Silver Age comic book and the animated series; he also attempted it in the post-Zero Hour continuity but was intercepted.
 * Saturn Girl secretly attempts to do this in two early Legion stories; both times someone else figures out what she's doing and manages to die in her place.
 * In the last few stories before the five years jump, the Legion finds a mystic seal that must be opened by such a sacrifice. One of them Magnetic Lad, younger brother of Cosmic Boy volunteers and dies indeed. It did the trick, though.
 * When Beast of the X-Men discovered the cure to the Legacy Virus, for some reason the first person to take it would die, but then it would spread throughout the world via air. Colossus took it and died. Don't worry, he came back.
 * An unusual villainous example: the alien Grandmaster once played a game (involving hero proxies fighting it out) with the incarnation of Death in order to bring his fellow Elder of the Universe, the Collector, back to life. Death didn't bother to inform him until the contest was over that the method involved required the Grandmaster to die in his place. Being the universe's ultimate game addict (and a pretty good friend of the Collector), the Grandmaster went through with it.
 * The whole deal was (or was later retconned into being anyway) part of a plan on The Grandmaster's part to ultimately.
 * The X-Men's Phoenix storyline started out with Jean Grey volunteering to get the X-Men back to earth by piloting an unshielded space shuttle through a lethal solar flare. What happened at that point is subject to debate, but it's fair to say only a miracle kept her alive.
 * In Sonic the Hedgehog, Dr. Finitevus uses magic and the Master Emerald to turn Knuckles the Echidna into a godlike being bent on cleansing the earth with fire...an effect that can only be reversed by someone giving up their life. Several of Knuckles' loved ones immediately volunteer, but it's his father Locke who ultimately goes through with the sacrifice.
 * Brought Up to Eleven when nine X-Men had to die in Fall of the Mutants. Needless to say, Death Is Cheap.
 * Thanks to Time Travel, this makes the Heroic Sacrifice of the first Hourman Rex Tyler even more complicated. Hourman must die fighting against Extant to prevent time and space from collapsing. Rex was given extra time in a time bubble by the third android Hourman Matthew so that he could spend some time with his son Rick the second Hourman. Rick tried to take his father's place in that moment in time so that his mom and dad could have a second chance at happiness. He and his dad then beat the hell out of each other trying to stop the other from giving his life. Ultimately, the android Hourman sacrifices himself so that the Tyler family will remain together.
 * Kinda subverted in the unpublished ending to Transformer: Universe, Featuring the Wreckers. When their ship has been shot and is going down, Rodimus tells everyone to get out while he takes the controls. He gets knocked out by Skywarp, who then takes the controls instead while everyone else gets out. When the ship crashes they mourn the now dead Skywarp

Film

 * Deep Impact - The entire crew of the Messiah decides to take one for the team, but it is still so everyone else can live.
 * Fridge Logic Sets in when you realize they had still several bombs on board they could of used at any time prior in the last 6 months. More Fridge Logic sets in when you realize the drive is an Orion Drive. Orion drives are a product of For Science! that are metal plates you put your ship on and have a nuclear weapon detonate on the other side of. The amount of energy being used to reach the comet and then match it's course to go back to Earth is a hell of a lot.... and if you pointed the engine at the comet the entire time there'd be a lot less comet.
 * Armageddon - Harry Stamper makes this choice when he defies the drawing of the lots to sacrifice himself, as the crew broke their remote detonator earlier in the movie.
 * Independence Day - Russell Casse's kamikaze attack with its characteristic moment of decision before stepping up to the plate.
 * Star Trek II the Wrath of Khan - Spock's Final Speech comes after he saves the day, but he knew going into the radiation flooded engine room was certain death.
 * And in Star Trek Nemesis where Data shows up at the last moment, transports Picard back onto the Enterprise, and blows up the Big Bad's ship immediately before the organic-matter-disintegrating-superweapon fires.
 * Consider the fact that the enemy's phlebotinum destroys only organic matter.
 * K19 The Widowmaker. If the first men going in weren't sure what was going to happen to them, those who saw them afterwards pretty much knew.

Literature

 * A Tale of Two Cities - Sydney Carton's switching places with Charles Darnay with one of the most memorable final lines in English literature, "It is a far, far better thing that I do, than I have ever done; it is a far, far better rest that I go to, than I have ever known."
 * The Black Cauldron - The undead-creating cauldron in the book can only be destroyed by a living person willingly crawling into it, shattering the cauldron and killing themselves. In the Disney film (very) loosely based on the book, they manage to bring back the one who made this sacrifice.
 * Harry Potter: Harry learns that in order to defeat Voldemort he has to  Subverted in that he manages to do this but.
 * Deep Wizardry, the second book in the Young Wizards, features this as a major plot point. A magical song/play must be sung/performed or the ocean will be corrupted, and Nita volunteers to play the part which is Killed Off for Real at the end of it, a fact she doesn't realize until she's well and committed. The Shark King (who is supposed to eat her) sacrifices himself to prevent Evil from interfering, and is eaten by all the sharks in the ocean, getting her off the hook (no pun intended, since she's a fish at the time).
 * No, she's a whale.
 * In fact the first book explains that defeating The Lone Power is perfectly possible but in every case Someone Has to Die (although sometimes it is in fact a different variation of Heroic Sacrifice involved, one death is inevitable when you oppose the Lone Power).
 * No, it says someone usually dies of his defeat. First book, Fred. Second, Ed'Rashtekaresket and how the HELL do I remember to spell that? Third, fourth, fifth, sixth, seventh and eighth books are respectively Peach, sort of, a whole bunch of people, nobody for the fifth because Mr. Otterface didn't die to accomplish anything, sixth nobody because the rules were different. Seventh book... well, everyone decided to Ascend to A Higher Plane of Existence and eighth book the author realized nobody had died lately so Roshaun died and Ponch and a bug also ascended. Super spoilers, HOOOO! It's not an ironclad rule. The side series cat books have a record like this as well.
 * In the fifth book, Nita's mother is dying of brain cancer, and defeats the Lone Power by acknowledging her own death. Book six takes place after her funeral. And book eight, no one dies.
 * In The Langoliers, by Stephen King, they figure out that everyone has to be asleep when they make the return trip, but the only effective method is lowering cabin air pressure. This is going to require someone to stay awake, using an oxygen mask, to be able to turn the air pressure back up to keep from killing everyone via hypoxia. That someone will not survive the return trip.
 * Turn up the oxygen. Take off the mask. In that order. Problem solved.
 * True, but then you don't have Redemption Equals Death.
 * In The Hitchhikers Guide to The Galaxy, the only way our heroes have of getting off the Sun Diver spaceship is if one of them operates the manual controls. Marvin the Android gets the call.
 * The X Men / Spider Man crossover novel series Time's Arrow resulted in an interesting double Someone Has to Die. At the beginning of the series, Cable is searching the timelines for his wife, dead in his own timeline, to have survived in a timeline where he didn't, so they can be together. He finally finds one. When the time comes to do the Someone Has to Die thing, he volunteers. His wife, of course, is the last to go, wanting a private moment...and then knocks him out, noting quietly how he never knew she was a "coward" who would take the easy way out in such a situation.
 * Twisted in the 3rd Megamorphs book: The deal struck by Ellimist & Crayak to allow the Animorphs to fix a Yeerk's time-machine meddling requires one of the team to die. Jake agrees, clearly expecting himself to be the doomed one, since Crayak personally hates him. Marco & Cassie both suspect this and secretly agree to jump in front of any bullet Jake plans to take. Jake does die on the mission, but not in the Heroic Sacrifice way anyone expected. Also, his death triggers the Ellimist's terms of the deal: the other Animorphs become invincible for the remainder of the book. Then, when they recover the Time Matrix at the end, the Animorphs flip off Crayak by using it to stop the entire crisis from happening in the first place, which means they never had to leave, which means Jake never had to die. One * POP* later, Jake's alive again.
 * In The Obsidian Trilogy, the price for some of the greater spells is the life of the caster, though they are always given the chance to turn down the deal, and it has nothing to do with life force, just that how they die advances the cause of the Wild Magic in some fashion.
 * In Darth Bane: Path of Destruction, General Hoth and 99 other Jedi sacrifice themselves to get the Brotherhood of Darkness to detonate the thought bomb that they had prepared, which would trap the souls of all involved for eternity. Hoth reasoned that the Brotherhood would only detonate the bomb if doing so would trap a large number of Jedi, and that the Brotherhood would otherwise escape and continue to plague the galaxy. Every Jedi present volunteered.
 * In Dark Reflections, the only one who can defeat the Big Bad is the Flowing Queen- in her true body( she's been sharing the main character, Merle's). the gang finds her true body, that of a Sphinx, but the Queen tells Merle the catch- in order to return to her body, the life force of her host must be exchanged with the form she takes on- and since her body is dead, it means Merle will die. Merle makes her peace with this, but the Queen tells everyone else that someone else can become her host and die in Merle's place. the love interest, Sarafin, offers his life, but Merle refuses to let him die. They Kiss and Sarafin uses the moment to take the Flowing Queen into his own body, then makes the transfer.
 * In Dark Reflections, the only one who can defeat the Big Bad is the Flowing Queen- in her true body( she's been sharing the main character, Merle's). the gang finds her true body, that of a Sphinx, but the Queen tells Merle the catch- in order to return to her body, the life force of her host must be exchanged with the form she takes on- and since her body is dead, it means Merle will die. Merle makes her peace with this, but the Queen tells everyone else that someone else can become her host and die in Merle's place. the love interest, Sarafin, offers his life, but Merle refuses to let him die. They Kiss and Sarafin uses the moment to take the Flowing Queen into his own body, then makes the transfer.

Live Action TV

 * Buffy the Vampire Slayer does this in the episode "The Gift". Not as much forethought as some examples, but there is still the dramatic pause, the weighing, the decision, the Final Speech and then Buffy's leap.
 * The series finale of Dollhouse, when Topher must trigger the mind-restoring machine himself - and be killed in the resulting explosion - so that the imprinted people outside can have their selves returned to them.
 * Stargate SG-1 episode "The Quest" had a good speech by Mitchell about it.
 * Supernatural almost had this with virgin Nancy in "Jus in Bello." Supposedly ripping out her heart would have saved everyone else. She volunteers and much moral debate ensues. Subverted when Dean says screw it and they go with a more risky (but arguably more heroic) plan, one without any Virgin Sacrifice. Doubly subverted when most of them die anyway, Nancy included. Unless Ruby was lying and ripping out Nancy's heart wouldn't have worked. It's a little confusing.
 * Also with regards to Dean's Deal With the Devil. He brings his brother back to life, but in return he will die (and go to Hell) in a year. But, if he tries to "welch or weasel his way out" of the deal, then Sam drops dead again. Naturally this creates conflict between the two brothers, and in the end, Dean is the one who dies.
 * In a second-season episode of Twenty Four, CTU discovers that the bomb they've been chasing all day has begun its countdown, which can't be stopped. Jack Bauer volunteers to fly it out into the desert, where its explosion will at least do less harm. Then George Mason, dying of radiation poisoning, stows away in the plane and at the last minute gives Jack a parachute and volunteers to crash the plane himself.
 * In Farscape, Stark decides to die, as the method by which the execution is carried out gives him--but none of the others--a chance to survive.
 * Or in Season 3 when Zhaan chooses to board the doomed Pathfinder ship, knowing that it will die with everybody on board, as she is already dying and will not allow Crichton to sacrifice himself. This is made even more heroic since there was a planet nearby where she could have healed, though she denies it would have worked, this was likely an attempt to make them feel better. (Best Death Scene ever as well.)
 * In the Season three episode of Eureka, 'I Do Over', Stark Sacrifices himself to stop a time loop that threatened to destroy the universe.On his wedding day!
 * At the end of season 3 of Lost, someone must swim into what they think is a flooded station to stop jamming the signal from the radio tower. Though Sayid and Desmond both volunteer, Charlie accepts that he is destined to die and takes on the mission.
 * The subplot for the Star Trek the Next Generation episode Thine Own Self revolved around Deanna Troi realizing that this situation pops up and that ordering someone to their death to save the ship is something a commanding officer has to do at times. She eventually accepts this, leading to her promotion to commander.
 * In Fringe 2X23, "Over There Part 2," William Bell realizes that in order to have enough power to return the group to their own universe, he will need to create a nuclear reaction using the instability of his body's molecular state.

Religion & Mythology

 * The Bible: Jesus had to die and suffer punishment for mankind's sins, in order to make it possible for people to be saved and not have to suffer punishment for their own sins.

Tabletop RP Gs

 * One of the six possible endings to the original Dragonlance adventures for Dungeons and Dragons stipulates that one of the player characters must throw himself into a portal to the Abyss in order to seal it from the inside, and thus stop the dark goddess Takhisis from returning to Krynn. Another of the endings is that Berem, an NPC who carries a piece of one of the foundation stones from Takhisis' temple in his chest, making him immortal, must return the stone to its rightful place, which would seal the portal but cause his own death. The latter ending was eventually used for the novelization of these adventures, the Dragonlance Chronicles trilogy.

Theatre

 * In the ending of Gilbert and Sullivan's The Sorcerer, one of either Alexis or Mr. Wells must be sacrificed to nullify the effects of the Love Potion. Of course, the sorcerer who made the Deal With the Devil is the one supposed to go down to hell, but many audiences today would rather have Designated Hero Alexis be the one to die.

Videogames

 * Final Fantasy X drives most of its entire plot on this trope, but subverts it. Even though every member of the party (minus Auron) volunteers to become the Final Aeon, Yuna won't let any of them die, and they end up killing Yunalesca, who offers this, along with the MacGuffin. But at the very end of the game,
 * Final Fantasy VII has another subverted example. The gang discovers that an ancient temple is in fact the MacGuffin they need and transforms into it by solving various puzzles, which can only be done inside. Meaning that whoever is inside to activate it will be crushed and die. The subversion comes when Cait Sith volunteers as his body is just a toy being remote controlled and thus it can be done with no death. The result is a fairly Narmy scene when it plays out acting as if it is some sort of noble Heroic Sacrifice when he does so even though his replacement comes around immediately afterwards.
 * Persona 3 features a rather sadistic twist on this trope: Ryoji, who turns out to be the herald of the Anthropomorphic Personification of death, willingly offers to let SEES destroy him -- an act that will rob you of all your memories of the Dark Hour and allow your deaths to come instantaneously, painlessly and unexpected when said personification finally descends to Earth and annihilates all life upon it -- in order to save you all from what he views as needless suffering from futilely trying to Screw Destiny.
 * And then played completely straight when the Main Character sacrifices himself to stop said Anthropomorphic Personification from killing everyone.
 * At one point in Fire Emblem 4, Julius and Ishtar run out onto the field to see who can kill one of Celice's troops first. They won't leave until they kill someone or you manage to defeat one of them. Considering their godly stats and super powerful tomes, if you're not extremely careful, you might find your little guys pulling straws.
 * And in the prologue of Fire Emblem: Shadow Dragon, you have to sacrifice one of your units to decoy Jiol away from Marth.
 * Starship Troopers: Terran Ascendancy has a level where the remote detonator of the Self-Destruct Mechanism of a research facility that must be destroyed has been disabled by bug attacks. Sergeant Rock Major Bishop has the player select one of his men to stay behind and manually trigger the bomb while the rest of the strike team abandons the planet before it is overrun. This troper would have found it difficult to choose, if it weren't for the fact that he had just rescued and taken command of a squad of extras during the mission, none of whom were of high enough rank to use more powerful weapons or wear a Marauder Battlesuit.
 * Subverted in Xenosaga Episode I, in which KOS-MOS volunteers to stay behind and manually operate the procedure that will break the giant space weapon up into pieces small enough to burn up in the atmosphere. She ends up not dying, but it's a very, very near thing.
 * Played straight in Episode III, when Jin leave Shion to assist chaos, KOS-MOS and Fei (sorry: Abel). The problem is, while the three characters are the messiah, his female equivalent and god, and are actually able to survive the last battle, even if is means taking A LOT of damage. Jin, on the other hand is just a former soldier with a cool looking sword...
 * Subverted at the end of Quest for Glory 5. The prophecy says that someone must sacrifice his life to seal the Dragon back in the can. If the hero volunteers, he will likely get a More Expendable Than You . But a proper hero will decide to Screw Destiny and just slay the hell out of the Big Bad.
 * A particularly poignant part of Tales of the Abyss invokes this trope: the only surefire way to neutralize the poisonous miasma covering the world is to cause a "hyperresonance" so powerful that it would take the user's life and the lives of thousands of willing sacrifices. The thousands of sacrifices are supplied by eventually-all-too-willing replicas, and Luke and Asch argue for a while over who should be the one to instigate the hyperresonance. It eventually ends with Luke trying to do so, but Asch needing to contribute a bit of his power anyway because Luke isn't strong enough on his own. Possibly for this reason, though it's never quite explained, both of them survive.
 * On the other hand, Luke, and it's implied Asch as well, soon find out the phlebotinum in their bodies is dissipating, leading to their own eventual death-by-dissipation. Funnily enough, neither of them last long enough for said dissipation to kick in, as they both end up performing more standard Heroic Sacrifices by the time the credits roll. And one of them comes back. Who knows which one?
 * Fallout 3. What would have otherwise been a Tear Jerker turns into a Crowning Moment of Stupid when you realize that you probably still have your radiation-immune Super-Mutant in your party, who just did this same thing mere hours ago game time, but he opts out Because Destiny Says So. You can also have another ghoul or a robot with you, both of whom would presumably be immune to radiation. To top it off? Rad-X magically stops working the moment the final cutscene happens, and this came at the end of what was - up until that point, a damn good third act.
 * Changed in the Broken Steel DLC to fix those complaints of the fridge logic.
 * You also survive in the DLC, when the Brotherhood pulls you out of there. The cutscene is unchanged, though, still showing how you died...before you open your eyes again.
 * In Tales of Symphonia, that's the entire purpose of the Chosen. Also, at one point, Botta and two nameless Renegades trap themselves in a flooding room in order to stop the self-destruct sequence of an underwater Desian Base. Yuan doesn't seem surprised, hinting that at least someone was expecting this.
 * And later on, all supporting characters left in the cast do this as a part of the sequence of false Heroic Sacrifices that reduces the party to Lloyd alone, while climbing the Tower of Salvation. Only in the cases of Raine and Genis does it seem a knowing choice of unavoidable death, the other cases looking more like accidents with a possibility of survival ("I'll get out of this mess on my own, you hurry on, you can't afford to lose any time !"), but a Z-skit springing up right before the first "sacrifice" shows Regal and Raine calmly discussing this, acknowledging the fact that they're more expendable than Lloyd. Right before that whole sequence, Zelos invokes this if you follow Kratos' path.
 * At the end of the Rise of the Zilart expansion for Final Fantasy XI Lion uses her body to stop a chain reaction that would destroy all of Vana'diel. After the end of the next expansion she got better.
 * Hoo boy, Mass Effect. Part of what makes the Virmire mission such a Wham Episode is its implementation of this very trope. Basically, Shepard and his/her squad have to plant a nuke at a research facility in Virmire that's creating an army of genophage-less krogans for Saren. Unfortunately you can't save your entire party (since either Ashley or Kaidan is with a salarian force creating a diversion while Shepard sets the nuke) and you only have time to rescue either Kaidan or Ashley.
 * Mass Effect 3 turns this Up to Eleven. The entire galaxy is fighting against the Reapers, who are technologically superior and almost completely unstoppable (you can destroy them individually, but there's too many to kill them all). People will die. A lot of people will die. And you're going to regret every single one you didn't save, even if there was nothing you could do about it.
 * Brief note:.
 * With all the focus the Grey Wardens of Dragon Age place on sacrifice, this was pretty much inevitable. Turns out the archdemon, when killed, can simply possess the nearest darkspawn and be reborn. The Wardens, however, have darkspawn taint within them, so if one of them kills the archdemon, both it and the Warden in question are annihilated.
 * You can also Take a Third Option by impregnating Morrigan, who can transfer the soul into her unborn child. Provided you trust the the shifty, unscrupulous witch with raising a baby god, this choice ranging from a no-brainer if you're already romancing her to a Player Punch if you're a female romancing Alistair (who'll have to be the father).
 * In Halo Wars, the Spirit of Fire is trapped inside a Forerunner shieldworld. In order for them to escape, somebody has to take the ship's FTL Drive and use it to destroy the artificial sun. This is combined with More Expendable Than You when Sergeant Forge tells Jerome that humanity will need every Spartan they can get to fight the war and so decides to take the latter's place.
 * Happens again in Halo Reach, also involving an FTL drive turned into a bomb. In this case it's the "damaged detonator" scenario, leaving Jorge to toss the player character out of the ship they were trying to teleport to oblivion so he can detonate it himself.
 * In Fatal Frame, every 10 years a young woman is brutally killed in order to seal a gate to Hell. While the victim has no choice in the matter, refusing to accept their fate results in the seal being too weak to hold the gate shut.
 * The Heroic Sacrifice of Kyrie at the end qualifies too.
 * Left 4 Dead: at the end of "The Sacrifice" campaign one player must jump off of the bridge, back into the swarm of zombies, to reactivate a failed generator and allow the remaining players to escape. In-game, the sacrifice can be anyone. Canonically, the one to die is Bill.

Webcomics

 * In Goblins the titular characters are being pursued by Kore. Their only escape is to flee into a dungeon crawl, but the approach will leave them wide open to attack from his ranged weapons.  stays behind to delay Kore long enough for the others to reach safety,.
 * In Homestuck, someone has to set off a supernova to trigger the "Scratch" that will reset their unwinnable session. The original plan to sacrifice a dreamself has been sunk by, so someone has to die.

Western Animation

 * In the original Justice League finale, "Starcrossed", the League decides to drop the Watchtower on top of the enemy's main base and Batman realizes that without manual steering, the station would miss the target. Instead of telling this to Flash and J'onn, he jettisons them in an escape pod and takes over the controls himself (Fridge Brilliance: he is the creator of the Watchtower). He doesn't die, of course, as he is bailed out by Superman just moments before the impact.
 * Name any variation of Optimus Prime/Primal from Transformers. Chances are he's offered himself up to die.
 * A case could also be made for
 * In Avatar: The Last Airbender, Yue does this during the first season finale, choosing to sacrifice her life in order to give it back to the Moon Spirit, which had been killed by Zhao. Sokka of course begs her not to, and the two of them have a nice tragic farewell moment. In the movie, her farewell speech is even more drawn out... and starts to get into the Department of Redundancy Department, unfortunately.

Other

 * Subverted in Bionicle, when the Toa Inika are told they have to sacrifice one of their own to get to the powerful Mask of Life. Matoro takes the hit, feeling he's not action hero material like the rest of the team - but he's Only Mostly Dead and quickly brought back, as the willingness to sacrifice was what mattered and the actual death was irrelevant.
 * Later played straight when the Mask of Life actually had to be used, in order to revive the Great Spirit Mata Nui (the user would be sacrificed and his body converted into the life energy needed to do so). Matoro steps up again, but this time he's Killed Off for Real.