Immortality Inducer

These characters typically weren't born immortal, but they didn't let that stop them. They find or create an object, magical or scientific, that will grant them that which they seek.

This trope happens whenever a character is immortal through the agency of a physical object. How the object works can be very varied. It may be Powered by a Forsaken Child, thus invoking Immortality Immorality, or it could be powered by harmless Techno Babble.

The extent to which it works and what kind of Immortality it bestows also varies. It might only work on a single character, or it could work on anyone in the vicinity. It may also have negative side effects, especially if it's a prototype or created by a Mad Scientist. Said object will often be an Amulet of Dependency: they will typically lose that immortality if the object is destroyed or sometimes just if they lose contact with the object, often resulting in No Immortal Inertia.

In some cases, characters may try to merge with this item in order to gain its effects permanently. This may work, or it might backfire horribly, depending on the story and what the object is.

There are typically three forms this trope can take: the object simply existing grants them immortality, the object must be used in some way periodically to keep them immortal, or the object must be worn or carried in order to make them immortal.

Likely to be a MacGuffin or Plot Coupon. If the Immortality Inducer can be mass-produced, it may lead to a Society of Immortals.

Supertrope to Soul Jar and Heart Drive. Subtrope of Immortality.

Contrast Artifact of Death.

Anime and Manga

 * Bleach: the Hogyoku was originally created to eliminate the barrier between shinigami and hollow. Later, it is revealed to grant the heart's truest desires; assuming the Hogyoku is exposed to twice captain level reiatsu, and that one has the inherent potential to fulfill their wish. And then...?
 * In One Piece, some devil fruits give their user immunity to some lethal attacks. To gain such immortality, a person has to eat a devilfruit.
 * Logias are immune to everything except their natural weaknesses, devilfruit weaknesses or haki users.
 * Buggy is immune to slashes. Even Mihawk, the 'greatest swordsman in the world', couldn't kill Buggy with his sword.
 * Brook's power is the closest to immortality of any of the fruits. After dying, his ghost was able to reanimate his skeleton body. With a lack of organs, most attacks cannot kill Brook, though he can still suffer pain and be defeated in battle. Brook can also turn into a ghost by escaping his body.
 * The Grand Panacea from Baccano! has this effect; anyone who drinks it ceases aging and almost immediately recovers from any injury (seriously, if they're burned the ash turns right back into flesh). The only way to "kill" an immortal is for another to absorb them (which gives them their memories in the process). There's also lesser versions of it that grant invulnerability and the weakness to being absorbed but not immunity to aging.
 * In Zombie Powder, various "powder hunters" search for the Rings of the Dead, which when brought together produce a substance called Zombie Powder that can be used to either raise the dead or grant immortality to the living.
 * Rin and Mimi in Mnemosyne became immortal when "time spores" entered their bodies. They can sustain severe injuries and regenerate themselves fully, as is shown with the often gruesome stuff that is inflicted on Rin. There is one character in the show who actually eats time spores, preferably old ones, so Rin and Mimi still have to watch their step.
 * The Philosopher's Stones in Fullmetal Alchemist. Every character laying claim to immortality possesses at least one, allowing them to regenerate from injuries (including fatal ones); however, this expends their Philosopher's Stones, meaning that a sufficiently tenacious opponent can still kill them. It's also possible to destroy their Philosopher's Stones directly through alchemy, or even rip them out
 * In Fairy Tail, during the Tenrou Island arc
 * Samurai 7 has a ruler enthroned in a machine that prolongs his life.
 * Both Yukiko and Liselotte Werckmeister from Eleven Eyes share the same immortality that comes with an rapid Healing Factor and the inability to age. It is revealed that the Voidstone is the source of the immortality and separating it from the host will disable that immortality.
 * In L. Jagi Lamplighter's Prospero's Daughter trilogy, Prospero and his children are immortal between the effects of Miranda's Water of Life, and Eramus's staff's ability to cure.

Comic Books

 * One anthology issue of The Tomb of Dracula featured a underground pool of blood that made any mortal contacting it immortal.
 * Superman and Batman Generations: There is a pool that makes a person submerged in it immortal, but two people have to enter together and one of them will die.
 * The Lazarus Pits used by Batman archfoe Ra's Al Ghul and others can rejuvenate the dying. Ra's Al Ghul is hundreds of years old thanks to the Pits.
 * Marvel Comics' Ulysses Bloodstone is immortal because of a meteorite/gem shard stuck in his chest. At the end of his story, it gets surgically removed by some bad guys and he dies.
 * The Sphinx, an enemy of Nova, was an Ancient Egyptian Priest given immortality and great powers by a gem he found in a mysterious temple. But he came to regret living for thousands of years; his main motivation was to find a way to end his own existence.
 * Vandal Savage was a Cro-Magnon man named Vadar Adg who found a strange meteorite that fell to Earth one cold night. He fell asleep near it, being bathed in its rays during the night, and he woke up an immortal being. However, the meteorite's effects aren't permanent; Vandal occasionally needs to eat the flesh and organs of his own descendants to maintain his immortality.

Fan Works

 * The Detian retrovirus in Undocumented Features. It's only available thanks to a Sufficiently Advanced Alien who gives it out as a reward for service to the galaxy and life (and with one very notable exception it can't be reverse-engineered).  Unlike many other examples, though, the immortality it grants is inheritable and passed on to the recipient's offspring.

Film -- Animated

 * In Tangled, the magic flower and later Rapunzel's hair serve this role for Mother Gothel. Singing the magic song restores her youth.

Film -- Live-Action

 * The League of Extraordinary Gentlemen. Dorian Gray's portrait, as in the original novel The Picture of Dorian Gray.
 * In Indiana Jones and the Last Crusade, remains alive (but frail) by drinking from the Holy Grail.

Literature

 * The Picture of Dorian Gray: the caveat is that the immortality wears off if the titular picture is destroyed.
 * In Harry Potter and The Philosopher's Stone, the title object turns out to be one of these, as you might expect. It produces the Elixir of Life, which makes the drinker temporarily immortal.
 * In Gor, humans have immortality thanks to "stabilization serums" - shots - developed by the Caste of Physicians; basically, it's an immunization against old age. In one book, a woman from Earth actually gets de-aged from her 60s to age 18 or so thanks to the serum. The priest-kings, alien gods of the planet, have even more advanced stabilization serums which make them immortal until they decide to die, although they can be killed.
 * "Anti-gerosome" in Kurt Vonnegut's short story "Tomorrow And Tomorrow And Tomorrow" is a cheaply produced serum that stops ageing. This makes the world horribly over-populated, and static - one family's great-great-grandfather is still holding sway over all the descendants crammed into his home.
 * The Font of Immortality (the drink, not the typing) is one of the five artifacts in Fablehaven. The catch is that it must be drank from at least once a week (don't worry, it's infinite), or else the drinker will spontaneously turn to dust.
 * The Lord Ruler's bracers in Mistborn, which work due to the fact that . They're made of atium which  . Add his other magic system, Allomancy, which lets him draw power from the metal itself-  . This neat trick is called "compounding", and was the source of his godlike general abilities, though only the bracers are this trope.
 * In Megan Whalen Turner's The Thief, Gen (the titular character) is recruited to help find a stone that grants immortality to whoever is wearing it.
 * from The Night Angel Trilogy by Brent Weeks.
 * Wowbagger the Infinitely Prolonged from the Hitch Hikers Guide to The Galaxy series gained immortality during an incident with a particle accelerator, rubber bands, and a liquid lunch.
 * The Denarians in The Dresden Files are immortal due to the presence of the Fallen Angel contained in the silver denarius coin each one carries. Furthermore, Nicodemus is given extra protection by the fact that he wears the noose Judas Iscariot supposedly used to commit suicide around his neck, which allows him to regenerate damage that would drop even other Denarians who are protected by their respective Fallen.
 * In John C. Wright's Golden Age trilogy, nomenual recordings allow effective immortality. Although it is a major plot point that the heat death of the universe will ensure that this is not actually living forever—the most that is possible is until every form of energy in the universe is completely consumed.
 * In Robert E. Howard's Conan the Barbarian story "The Tower of the Elephant", Yara is said to be centuries old, and immortal because of his gem, the Heart of the Elephant.
 * In Lord of the Rings, this is one of the things the One Ring can do. Gollum's unnatural age is thanks to it. The Nine for the Nazgul also serve this function.
 * In The History of the Runestaff, King-Emperor Huon's life is indefinitely prolonged by the Throne Globe, an elaborate piece of Lost Technology. From the outside, it looks like a glass sphere full of translucent fluid in which Huon floats. He can talk to people in the room, but he can't leave the sphere or move it. If it were to be destroyed, which would not be terribly hard considering it's made of glass, he would die. This is the Ur Example of this kind of life prolongation (1967) as far as I know. (I don't think Huon is ever explicitly called a God-Emperor, but he otherwise fits the trope; for instance, people swear "By Huon's Teeth".)
 * The narrator in Xanadu by Rush gains immortality after entering the Pleasure Dome, dining on the honeydew, and drinking the milk of paradise. He is not happy about it.
 * In Dragonlance, Fistandantilus's bloodstone pendant allowed him to drain the life-force from other wizards to prolong his own existence..
 * In the Old Norse Tale of Norna Gest, the magic of a norn makes Norna-Gest immortal so long as a certain candle is not destroyed.
 * In Ursula K. Le Guin's Changing Planes, one world that the narrator visits has an island which has a small population of immortals, whose eternal life is believed to be granted by the mosquitoes that are endemic there. Unfortunately, this is Type VI immortality, with a normal human ability to heal. The immortal that she is fortunate enough to meet is a withered husk after having survived falling into a lava stream. The natives don't seem to worry about this fate because, according to them,.

Live-Action TV

 * In Doctor Who, despite regaining a set of regenerations, the John Simm version of the Master forces himself not to, storing his essence inside a ring to revive himself later.
 * Similarly, the Kastrian Eldrad was blown into a single hand. He and his entire race could store their genetic imprint into a ring to be reawakened with a burst of radiation even after over a hundred million years.
 * Then there's the Time Vortex, which can do virtually anything. When Rose absorbs it, she uses it to revive the recently-killed Captain Jack Harkness. However, since she is an inexperienced "Time Goddess", she ends up reviving him permanently (essentially setting his "revive" setting to "always on"). Nothing can kill him (unless ).
 * Space: 1999 episode "The Exiles". Two prisoners have extended lifespans due to skintight membranes covering their bodies. If the membrane is ripped and their bodies are exposed, they're subjected to Rapid Aging and die.
 * Goa'uld sarcophagi in Stargate SG-1 are best described as Autodocs, but they're so effective that they can raise the dead. The System Lords are thousands of years old thanks to them. Shame about the side effects.
 * As evidenced by Lord Yu, even a sarcophagus can, eventually, prove useless, if a symbiote is extremely old. Yu is shown to be suffering from the Goa'uld version of senility, such as ordering fleets to a battle that was fought long ago. His First Prime complies, of course, but then conspires with Teal'c to turn command of the fleets over to Ba'al. Ba'al is, at first, outraged that a First Prime would betray his god, but relents after Teal'c suggests offering the deal to a rival System Lord.
 * In Torchwood: Miracle Day, is this, coupled with.

Mythology

 * The Fountain of Youth.
 * This was said to be one of the many effects of the Philosopher's Stone.
 * The ultimate goal of Chinese alchemy, rather than the western "lead into gold," was to create an elixir that granted immortality.
 * For some western alchemists, the point of turning lead into gold was also to create an elixir of immortality: the the thinking was that gold is the purest metal, and transmuting the base dross of lead into gold would mean turning common flesh into angelic perfection.
 * In Chinese Mythology, the Peaches of Immortality grow in the garden of the Jade Emperor of Heaven and are given to gods, sages and others deemed worthy of them.
 * In Greek Mythology, the food of the gods, grows on Mt. Olympus and grants their immortality.
 * In Norse Mythology, the gods maintain their immortality by the eating of golden apples cultivated by the goddess Iðunn. You might be noticing a pattern here.

Tabletop Games

 * The CCG Illuminati had the card Immortality Serum, which not only made the affected character indestructible, it could be played on an opponent's characters to make them defect!
 * Magic: The Gathering has The Fountain of Youth, which gives players a cheap method of increasing their life points. Only the pigeons ever discovered its secrets, since no one in their right mind would drink from a dirty public fountain (especially if pigeons bathe in it).
 * Call of Cthulhu (tabletop game) campaign The Fungi From Yuggoth. The Villain Lang Fu has worn his Coat of Life for centuries, as it grants him long life. If it is ever removed from him for more than a few minutes, he will suffer from Rapid Aging and die.
 * In Warhammer 40,000, the life of the God-Emperor of Man is preserved by technology in his throne. Probably influenced by the Runestaff books; certainly much better known nowadays.

MMORPGs
"This Witherless Rose will wither away instead of you... This Immortal Heart will cease to pump blood, instead of yours. This Diamond will turn to dust in place of your mortal body."
 * In Ragnarok Online, the Soul Linker job change implies that your character owns several.

Video Games

 * The Trope Namer is the +ii emitter in I Miss the Sunrise, affectionately referred to as the "immortality inducer" by some characters. It works by emitting radiation that stops cell aging, and is mass-produced, effectively making the entire human race immortal. It induces type II immortality.
 * In the sequel, The Reconstruction, it is also
 * in Time Splitters achieves immortality by merging himself with one of these, or turning himself into one, it would seem. The good? He is immortal and can time-travel at will. The bad? His body is plastered to a giant bipedal mech, and he has absolutely no hands whatsoever.
 * In Metal Gear Solid 4: Guns of the Patriots,
 * The Touhou series has the Hourai Elixir, which was literally created by distilling the concept of eternity into liquid form. It makes whoever drinks it immortal by removing the very concept of death from their being: they will never age, never grow sick, and will instantly heal any injury, no matter how severe. The closest one can get to defeating one is beating them down until the pain makes them not want to fight you anymore. Fortunately, only two people have consumed the Elixir, neither of whom is particularly interested in a fight to the death (except between each other).
 * In Pokémon Ranger: Guardian Signs,
 * The Heart of Chaos serves this purpose for Caius of Final Fantasy XIII-2. As long as it beats in his chest, he always revives instantly after being defeated, Justified via him having the Auto-Raise status boost. If it's destroyed, he dies
 * Miss Fortune of Skullgirls, upon swallowing the Life Gem. She was cut into pieces shortly afterwards, though not only did she survive the ordeal, the gory extent of splitting apart her undying body is utilized in her fighting style.
 * Igos du Ikana, Igos du Ikana's bodyguards, Flat, Sharp and every undead inhabitant of the Ikana Canyon in Legend of Zelda: Majora's Mask revived by Skull Kid wearing the Majora's Mask and mantained alive by Twinmold.

Web Original

 * From the SCP Foundation, there's SCP-963, a talisman which, if you are killed while holding it, is imprinted with your soul. From then on, anyone else who touches the talisman has their personality overwritten with whoever is contained inside. It's actually possible to make multiple copies of yourself this way.
 * Anyone who touches SCP-596 is kept alive forever until they release it, even regenerating from any injury. Not that you would want to be however, since you're kept alive in permanent agony, and the only way to let go is for someone else to touch it at which point you die. Its heavily hinted that it was a booby trap to curse tomb robbers with a case of And I Must Scream.

Western Animation

 * Starscream, in Transformers Animated, becomes immortal due to a shard of the AllSpark lodged in his head.
 * The Dog talisman in Jackie Chan Adventures gives someone immortality with youthful energy, but (the baddies, at least) can still feel pain from blunt force trauma. The Horse Talisman could probably provide From a Single Cell-type immortality, although its regenerative powers was never taken to the limits in the show. Together, they provide Complete Immortality.