Negate Your Own Sacrifice

The characters are in a situation that can only be resolved with a Heroic Sacrifice. So they send someone who can't die (or is already dead) to "sacrifice" themselves.

For example, Superman "sacrificing" himself by throwing himself over a grenade. Superman is, well, Superman. He is not affected by a mere grenade, It would need to be made of Kryptonite to hurt him. Whether Superman knows it won't hurt him at the time is irrelevant to the trope, it only matters that it didn't affect him.

If the characters actually sacrifice themselves in a way that doesn't mitigate the sacrifice, that's not this trope.

Counter Trope to Stupid Sacrifice. Compare Good Thing You Can Heal.

Anime and Manga

 * Since all Digimon in Digimon Adventure reincarnate eventually, given enough time, this applies to them. Specific examples include Angemon in the original, and Wormmon in its sequel, Digimon Adventure 02. Both sacrificed themselves for their Chosen Child partner and both were up and about in their baby forms within the next two episodes.

Film
"The Bowler: "Now, the good news is you're not going to die, because you're already dead.""
 * The Cheshire Cat takes a beheading for the Mad Hatter in Tim Burton's Alice in Wonderland. This trope applies because the Cheshire cat can detach his head from his body at any time.
 * The Bowler throwing her ball (containing the spirit of Carmine the Bowler) into the Psychofrakulator in Mystery Men.

Live-Action TV
"Nathan (RE: a virtual stranger who's just been killed in front of the group): Better him than me! Curtis: You can heal. Nathan: Better him than one of you!"
 * In the Doctor Who episode "Utopia", a launch can't be completed unless someone goes into a deadly-radiation-filled room to flip some switches. They just so happen to have Captain Jack Harkness - a man who can't die - along, so he goes in to do it.
 * Happened in Farscape. Aeryn, Crichton, D'Argo, Zhaan, and Stark are all captured while aliens tried to figure out who attacked one of their ships (they had all been aboard Talyn when he had opened fire, then escaped leaving them to get caught). Everyone tells a different story, so in the end the annoyed aliens declare they'll execute ALL of them by disintegration. Stark then 'admits' to the crime, whispering to the others that his powers gives him a reasonable chance to recover from disintegration; the only reason he hadn't volunteered from the start was that he didn't know what method of execution they'd use. Sure enough, he's disintegrated, the others go free, and some episodes later he reappears, having 'reintegrated' thanks to his powers.
 * Subverted by Nathan from Misfits.


 * However, he does later volunteer himself (very reluctantly) to be temp-killed to save the others, although he doesn't actually have to go through with it.

Literature

 * Harry Potter: During Dumbledore's duel with Voldemort, Fawkes the phoenix swallows a killing curse; instead of dying, he just goes from his fully-grown form to a chick.
 * In the final book,
 * In the second book, someone avoids death by the Basilisk, being only petrified, because instead of seeing the Basilisk's eyes directly, he saw them through Nearly-Headless Nick, a ghost. It's not clear whether Nick took the full blast of the Basilisk's power deliberately or just happened to be standing between the student and the basilisk.
 * Played with in Charmed Life. Cat (who has nine lives) is going to be killed so that his evil sister can stay in her new alternate reality. He's pretty okay with it since it will mean that he won't have to deal with her any more and since he has lives to spare, unlike any other potential sacrifice. Of course, his sister shows up to tell the people about to kill him that they'll need to kill him a few times since he has several lives left. At this point, Cat realizes just how evil his sister is.
 * In The Dresden Files book Death Masks,

Myth and Legend

 * There's a children's story about seven brothers who all look identical, but each has a different magical immunity (one is immune to fire, one cannot drown, one can't be cut, and so on). One of the brothers is unjustly sentenced to death, but when the method of execution is announced, the brother who is immune to that death secretly takes his place, and after a week of trying different methods of execution and getting nowhere the authorities give up and let him go.
 * A variation of this is found in the book The Five Chinese Brothers, where one of the brothers did cause the death, but only because he couldn't hold the sea in his mouth any longer (and tried to signal the boy that drowned.)
 * For the record their powers are Swallowing the Sea, very strong neck, very light, can stretch his legs, and can hold his breath for days.

Toys

 * Zigzaged in Bionicle. One of the Toa Inika has to volunteer for a sacrifice so they can claim the Mask of Life. Matoro volunteers. So he dies. Immediately after this, he is revived, because the mask was testing his willingness to sacrifice himself. However, actually using the mask kills you, and once again Matoro volunteers.

Video Games

 * Averted in Fallout 3, to the anger of the fans - none of your . That was fixed in the expansion pack, but Ron Perlman still calls you a coward for not doing it yourself. Pragmatism is dead in the wasteland.
 * Final Fantasy VII has Cait Sith volunteer to stay in the incredible shrinking temple, because he's only a stuffed toy and his controller is elsewhere. A few minutes after he does so, Cait Sith No.2 joins the party (who turns out to be indistinguishable from No.1. He's even got the same equipment No.1 had on him when he got crushed into a singularity.)
 * At the end of Raidou Kuzunoha vs. the Soulless Army takes a ride on a missile to make sure it hits its intended target. He even notes his actions won't really kill him (hence why he is back in the sequel).

Web Comics
"Gav: Does it count as a selfless sacrifice if you clone yourself before your suicide mission? Kevyn: I'm putting it on my resume and hoping nobody asks."
 * In Schlock Mercenary, while being held prisoner, Kevyn jury-rigs a gravity pulse that takes out the guards, which has the nasty side-effect of killing him as well. Good thing he gate-cloned himself first.

Western Animation

 * In one episode of Batman: The Brave And The Bold, Batman sends an alternate-Earth-destroying bomb as the timer ticks down to
 * Kenny from South Park has done this a few times, since he knows he keeps coming Back From the Dead.
 * Well, hard to say; a recent episode makes it sound like he's always known, but whether or not he (or any other character) notices his repeated deaths has usually varied from one episode to another. Still counts as this trope, though.
 * Played with on Avatar: The Last Airbender: Azula shoots lightning at Katara, so Zuko, who's been taught to deflect that attack, jumps in front of her. He still gets massively injured since he didn't have time to do it properly (doesn't exactly mix well with a diving save), but he survives.