Immortality is the state of having an infinite lifespan possessed by Immortals, Original Vampires, Vampires and Vampire/Werewolf Hybrids. It affords the user immunity to the effects of aging and diseases, thereby granting the ability of outliving non-supernatural creatures.
It is worth noting that "immortality" in the world of The Vampire Diaries and The Originals, is not immunity to death; Elijah stated that every creature must have a weakness and that nature would never allow a truly immortal being to exist. This was, however, proven false as Silas and Amara were truly immortal beings; however, their immortality was capable of being stripped from them by The Cure, providing a loophole to reverse their true immortality instead of killing them.
- The first immortal beings, Silas and Amara, were unconditionally and truly immortal. They were immune to disease, age, and all forms of physical and magical death.
- They were only able to be killed after the Cure for Immortality was ingested and used to remove their immortality.
- As they could not be killed in any way, Silas and Amara's loophole to die was to reverse the immortality spell through the Cure.
- The Original Vampires are immune to natural death, physical aging, diseases, and traditional methods of vampire destruction.
- The Original Vampires, unlike true Immortals, have conditional immortality, as they can be killed by the source of their immortality, a stake carved from the White Oak Tree.
- An Original can be weakened by werewolf venom, which will eventually cause them to hallucinate, run fever, along with becoming crazy and paranoid. Though unlike normal Vampires the effects are only temporary and they will recover within a day. Vervain can also be used to weaken and slow them down, though less so than a normal vampire as they will heal from the effects much more quickly.
- Like all vampires, the Originals burn when exposed to sunlight without daylight amulets, but sunlight will not kill them.
- Though they can't be killed permanently by regular wooden stakes and weapons, a wooden stake through the heart will neutralize an Original Vampire briefly, appearing as if they were dead, but they will revive within one to a few hours.
- If an Original Vampire is stabbed through the heart with one of the White Oak Ash Daggers, silver daggers dipped in the ash of the White Oak Tree, or the golden dagger in Klaus's case, it will kill an Original Vampire, but only as long as the dagger remains in their heart. The daggers must be dipped in the ash before each use or it will lose its effect, even if it was removed for less than a minute.
- They can also be affected by cursed objects, though not being able to kill them. They can however suffer great damage, or be neutralized in a desiccated, dead, and deep slumber state through the White Oak Ash Daggers, or be neutralized without being in a desiccated slumber through Papa Tunde's Blade, being awake but paralyzed, going through immense physical and magical torture with the blade being burrowed in the Originals chest.
- The only way to permanently kill an Original Vampire is to stab them in the heart with a White Oak Stake made from the White Oak Tree, or if enough magic is channeled against them as magic is stated to be able to kill all things if enough of it can be conjured.
- Vampires are immune to natural death, physical aging, diseases, and most illnesses.
- The only illness that can weaken or kill a vampire is werewolf venom, which will infect the wound and spread through the bloodstream. After that the vampire will start to hallucinate and cough up blood. Ultimately, the vampire dies rabid and paranoid.
- Vervain can also be used to weaken and slow down a vampire. Though in some cases Vampires have shown to grow at least somewhat of an immunity to its effects through taking small doses over a long period of time.
- Wooden bullets are usually used to weaken and with proper aim even kill vampires.
- The only way to kill a vampire is to rip out their heart, burn or decapitate them, or the most well known method, a wooden stake through the heart. Magic can also be used to kill a vampire as magic is stated to be able to kill all things if enough of it can be conjured.
- Vampires will also die in the event that the Original Vampire who's bloodline they stem from dies, though this usually happens within a few hours after the original vampire's death.
- The Original Werewolf Vampire Hybrid, Niklaus Mikaelson, is immune to natural death, physical aging, diseases, the negative effects of sunlight, and werewolf venom.
- Because of his werewolf heritage Klaus is also affected by wolfsbane, but he cannot be neutralized by the White Oak Ash Daggers, nor by regular wooden weapons, albeit they still cause great pain.
- Kol and Davina, while Kol was possessing a witch named Kaleb, used magic to turn one of the silver bladed White Oak Ash Daggers into a gold bladed White Oak Ash Dagger that can be used exclusively on Klaus. As it is not silver, which does not harm werewolves, the gold blade provides a loophole that can now neutralize Klaus, just like the silver daggers neutralize his siblings. The golden dagger, however, was destroyed by Dahlia by melting it.
- The only way to permanently kill Klaus is to stab him in the heart with the White Oak Stake.
- Werewolf Vampire Hybrids are Immortal. Immune to natural death, physical aging, diseases, the negative effects of sunlight, werewolf venom, and several of the traditional methods of vampire or werewolf destruction.
- The only way to kill a hybrid is through decapitation or heart extraction.
- Witches can use spells and herbs to delay the aging process and live much longer than humans, but age will eventually catch up with them.
- Witches can cheat death for centuries using various methods of magic. Such as possession spells to transfer their spirits to a new body upon their death.
- Dahlia performed a century slumber spell on Freya and herself that prevents all forms of harm, granting them pseudo-immortality at the cost of only waking for one year before the cycle of slumber repeats. It is speculated that they may age in the year they are awake. They retain the magic that accumulates in their century sleep as they are not undead and cut off from magic like vampires, or transformed into a true Immortal like Silas. If they do not age, then by adding the century of sleep, they may have been able to keep their magic.
Immortality Spells are spells created by the witches Qetsiyah, Silas, Esther, and Dahlia. These spells were used to grant various forms of immortality to Silas, Amara, Dahlia, Freya and the Original Family.
- Qetsiyah was the first witch to create an immortality spell, with Silas inventing the idea of the spell itself and helping, and was used to immortalize Silas and Amara. The spell came in the form of an elixir that turned the pair into true immortals. The spell is incredibly powerful and is forbidden by the Natural Elements.
- Dahlia created and cast a spell to bestow physical immortality and delayed aging to herself and Freya. The spell renders them immune to physical harm and death such as poisoning or a broken neck and lengthens their lives by placing them in an ageless sleep for 100 years to awaken and experience 1 year of life before falling back into another century long sleep in an endless cycle. As they did not die and revive, they are not undead. Unlike Silas, they can still practice magic as Dahlia's spell accumulates their magic while asleep for a century.
- Dahlia adding the sleeping cycle may have provided a loophole in Nature allowing her and Freya to use magic as they are not free to roam the earth at all times for eternity as the Originals and Silas could.
- Esther created and cast an immortality spell on her family. She called on the White Oak Tree for immortality, and the sun for life, and turned her children and husband into the world's first and most powerful vampires known as the Original Vampires. Silas and Amara, while truly immortal, are not vampires despite feeding on blood, as they lack the powers and weaknesses and other attributes the vampires have.
- Blood is the life-force of an Immortal.
- The White Oak Tree is one of Nature's eternal objects and a source for immortality.
- There are three known ways to reverse the Immortality Spell and by extension, vampirism.
- The first and oldest was an Elixir created by Qetsiyah to be used against Immortals.
- The second was a ritual attempted by Esther to be used against Original Vampires.
- The final and most recent was a spell invented by the Travelers using blood from the last pair of doppelgängers and a minor version of the Magic Purification Spell.
- Witches can cast a spell that will allow them to grow old with for a year and sleep for a century to keep his youth, this spell has been used by Dahlia and Freya and so they were able to overcome death and are now alive for over 1000 years.