(Mortality, not morality)
An immortal character becomes mortal, usually via external means.
Overlaps with Nigh-Invulnerability when the immortality is due to invulnerability and no longer having the latter means no longer having the former. Commonly done to Big Bads so that they can be killed. Sometimes such a way is sought by the immortals themselves. At other times the way is avoided at all costs.
Sometimes results in (a usually rather gruesome scene of) No Immortal Inertia.
Related to: Brought Down to Normal or I Just Want to Be Normal, Being Human Sucks, Humanity Ensues. Contrast Immortality Inducer for ways for a mortal to become immortal. Closely-related to Immortal Breaker, a weapon or spell that can supersede immortality to kill immortal beings. The chief difference is that this trope kills indirectly, while Immortal Breaker kills directly.
- Lyrical Nanoha: After being separated from the Book of Darkness, the Wolkenritter lose their Resurrective Immortality and slowly become normal (well, normal in the context of a World of Badass where Everyone is a Super) over the course of the next several years. Notably, they're all perfectly content with this, since it allows them to live out their first and final lives with their beloved master Hayate.
- Wonder Woman: In the New 52 continuity Apollo strips Hera of her immortality and divinity, turning her human, after he becomes the new king of Olympus.
- In Lucifer, Lucifer orders all immortals from his Creation on pain of death. When Mona, who is sent to enforce his will, encounters a broken-down immortal who has just been through a major case of Love Hurts, she allows him to choose between exile, death, or his immortality. This allows him to live out the rest of his life with his home and his best friend.
- In Disney's Hercules, Hades has his minions Pain and Panic kidnap an infant Hercules to feed him a potion that will turn him mortal so he can be killed, but because they miss the last drop Herc loses only part of his powers. Hercules becomes a full god again at the end of the movie, but chooses to go back to being "just" a demigod (and thus mortal) to live with his Love Interest.
- In The Mummy, it turns out that the companion book to the Book of the Dead doesn't kill the Big Bad when read from. What it does is remove his immortality, allowing him to be killed like a mortal. Imhotep, however, didn't know this and simply walks into a sword, assuming he'll be fine.
- Pirates of the Caribbean: The Curse of the Black Pearl has this happen to Barbossa at the worst possible time. He's among the pirates cursed with immortality for stealing Aztec gold, and the curse can only be lifted by returning all of the stolen gold. Will drops the final gold piece into the cursed treasure chest just after Jack Sparrow blows a fatal hole in Barbossa's chest with a pistol, removing the curse and causing Barbossa to bleed out.
Barbossa: Ten years you carry that pistol, and now ya waste your shot?Will: He didn't waste it. (drops coins)
- Part of The Prize in Highlander is the option to live as a normal human, which Connor states is his intention at the end of the original film.
- In Wrath of the Titans, the level of prayers to the gods has dwindled so much that the gods have lost their immortality and many have died before the movie even started. The gods who are left still have their powers, but they are fading and they are vulnerable to being killed.
- And Another Thing...: Wowbagger the Infinitly Prolonged wants to die, but can't because he's been made immortal against his will. At the end he become de-immortalized, so he will eventually die. Close Enough.
- The plot of Harry Potter and the Deathly Hallows was Harry and company searching for and destroying the Horcruxes in order to remove Voldemort's immortality.
- In J. R. R. Tolkien's Middle-earth, the members of the Half-elven family descended from Lúthien get the cosmic choice to which kind they want to belong, leading to (im)mortality and a different fate after death. Arwen from The Lord of the Rings, and before her her uncle Elros, choose humanity and mortality. Their ancestor Lúthien was Elven, but got a once-only cosmic exception to have a mortal fate to be with her human lover Beren, before and after death.
- In Skin Game, Uriel lends his Grace to Michael to use for a day, resulting in him becoming temporarily mortal. It is revealed when Harry punches him in the face and sees him actually bleed, which a being who can unmake galaxies should not do.
- In the same book, Nicodemus temporarily takes off Judas' Noose which makes him invincible to anything but being strangled with itself, for a ploy.
- In The Tale of the Body Thief, Lestat swaps bodies with a human for a day in order to feel what's it like being mortal again. Unfortunately, the other guy turns out to be a con man and a thief, who absconds with Lestat's body, while Lestat is trying to figure out what to do with being squishy and vulnerable again and needing things like food and shelter. He gets his body back at the end.
- Star Trek: The Next Generation: In an episode Q had his omnipotence taken away as a punishment by the Q continuum, thus becoming mortal. The Enterprise crew are saddled with him until he regains his immortality—in fact, he specifically chose them because he knew that they are idealistic enough that in spite of their own dislike of Q, they would still protect him from other creatures who might desire revenge on Q for his past torments.
- Star Trek: Voyager:
- 7 of 9 hurt her hand while working and was upset with the fact that supressing the Borg nanotechnology removed her Healing Factor.
- Q once made his son q (yes, lower-case) mortal and dumps him on Voyager. It's less of a punishment and more of a disguised lesson.
- On Angel according to the Shanshu Prophesy, the Vampire with a Soul will eventually be rewarded by dying - which is to say, he'll be rewarded by becoming human, and thus being allowed to die as a human.
- Nathan from Misfits sells his immortality on the black market.
- Doctor Who: The clone of David Tennant's Doctor, grown from his severed hand and Donna Noble's human DNA. He has all the Doctor's memories, but only one heart and a normal human lifespan, which he chooses to spend with Rose on a parallel Earth.
- The final episode of Lost implies that Richard Alpert has lost his immortality, which he considers a very good thing.
- Torchwood: Miracle Day:
- Ash vs. Evil Dead: In the second season, Ruby loses her immortality that has kept her alive for centuries by that point, forcing her to ask Ash and co. for help when her demon offspring turn against her. She's eventually killed for good by a younger-and still evil-version of herself.
- In Season 4 of The Librarians, Jenkins willingly gives up his immortality to save Nicole, Flynn's first Guardian, to whom this trope happens minutes earlier, courtesy of Rasputin wielding Koschei's Needle. Several subsequent episodes deal with Jenkins trying to deal with suddenly being mortal after so long.
- In his best ending in SoulCalibur 3, Zasalamel succeeds in becoming mortal and spends the rest of his life as a scholar, chronicling everything he experienced.
- In Final Fantasy III, the great sage Noah awards each of his three students with a gift. Doga is bestowed with great magical power while Unei was given control over the world of dreams while she slept, and both go on to become renowned sages in their own right. Xande? He receives the "gift" of mortality. He doesn't take well to this perceived snubbing. In fact, he's so bent on avoiding death that he's willing to "live" forever by freezing time for himself and everyone around him.
- The Big Bad of Final Fantasy V, as well as the previous wielder or the Void, both lost their immortality when they acquired this power.
- In the finale of World of Warcraft Cataclysm the Dragon Aspects lose their immortality (and possibly more of their powers) after focusing their power through the Dragon Soul to slay Deathwing for good.
- This is the goal of the Nameless One in Planescape: Torment, in part due to the Immortality Immorality he's unwittingly using — whenever he dies, somebody else in The Multiverse gets the life sucked from them to restore him, causing them to linger as vengeful undead shadows.
- The Elder Scrolls provides several examples:
- This was the goal of the Underking in The Elder Scrolls II: Daggerfall, as a necessary component of being able to finally die — which puts him as one of the endings of the game, as to die he needs the Mantella (which will be destroyed by this), the thing everyone else is searching for to either power Numidium or become a god. Whether he pulled it off is uncertain, but trending 'yes' — indications are that the end of Daggerfall broke time and all endings happened as much as was possible without directly contradicting another in anything but cause, and the Underking's death would have been easy to slot in for Akatosh' servants.
- The Elder Scrolls III: Morrowind has the Tribunal, a trio of flesh and blood gods who ascended to that status by tapping into the heart ("divine center") of the dead creator god Lorkhan. The main quest of the game features the Nerevarine severing their ties to the heart in order to defeat the Big Bad Dagoth Ur, who also draws his power from the heart. Once those ties are severed, the Tribunal revert to mortal forms, which only happens, per Vivec (one of those deities), due to the faith of their followers.
- Daemons in The Alliance Alive are normally immortal, but near the end of the game Vivian is made mortal after being cursed by Kuwalsa. She presumably regains her immortality after you beat him.
- Fate/Grand Order: This becomes a problem for the heroes in the Babylonia chapter, as they are up against Tiamat, primordial mother of all life. Putting aside Tiamat's enormous raw power, she is the "alpha and omega" of all life, meaning she cannot die until she is literally the only living thing left in the world. The heroes despair at this, as it seems like there's no way to kill her that doesn't involve killing themselves beforehand. They end up dropping Tiamat into Kur, the Underworld. Since there are no living things in the Underworld, by definition, Tiamat is therefore the only living thing in that "world". Unfortunately, this still isn't enough: all the spirits of the dead and Ereshkigal herself are unable to kill Tiamat, and she begins to climb back out. So instead, King Hassan, the original Assassin, sacrifices the majority of his power to turn his sword into a one-time Conceptual Weapon that inflicts "mortality" on its target. This robs Tiamat of her immortality, regardless of whether any other life exists, which finally allows the heroes to destroy her.
- Housepets!: This was the stake of the cosmic game played between 'Pete' the griffin and the Spirit Dragon: The loser has to spend an objective time period (as opposed to subjective time, which is over the moment it starts) as a mortal being. They both lose. A few story arcs later, we see them as what appear to be two foxes - still arguing, naturally.