Amelie: Have you children any concept of geometric progression?
Claire Danvers: [Claire raises her hand]
Amelie: And how many vampires would it take to turn the entire world into vampires, if it was so simple as that?" [Amelie smiled as Claire opened her mouth.] My dear, I do not expect you to answer, though if you would like to work out the math of it and tell me someday, I should be most interested to see it. The truth is that we came very near to it, in my younger years, when humans were much fewer. And it was agreed - as it has lately been agreed among you humans - that perhaps conservation of game is a wise idea. So we - removed the knowledge of how to create more vampires, simply by refusing to teach it.
Vampire-bite victims becoming vampires themselves is a staple of vampire fiction. However, if every bite victim turned, this combined feeding-and-procreation method would logically lead to vampires rapidly outnumbering their human victims. While many works leave vampire population logistics unexplained, others choose to address the population implications head-on, either by incorporating a Vampire Procreation Limit that prevents a vampire population explosion or using it as a variant on a Zombie Apocalypse plot.
A particularly common method, popularized by Anne Rice, is to require the new vampire to receive a transfusion of blood from an existing vampire in addition to being drained. But there are other possibilities such as requiring the potential vampire to have a specific gene or even making vampires a separate species that reproduce sexually.
- In Blood+ Chevaliers are produced by feeding a Chiropteran Queen's blood to a human dying of blood loss. The common, "feral" Chiropterans are artificial, produced via a drug isolated from Queen's blood. The Queens themselves though, reproduce sexually, they are born in pairs and eventually one Queen's Chevalier mates with her sister.
- In Hellsing victims of vampiric feeding do rise as the undead, but only virgins become vampires, everyone else becomes a flesh-eating ghoul. Which is why the vampire priest in the first chapter attempts to rape Seras Victoria before eating her, and Alucard asks if she's a virgin before shooting through her.
- Vampires in Karin reproduce sexually, but a good majority of them are infertile and have trouble conceiving. There are certain vampires known as "psyches" who are capable of bestowing fertility by sharing their own blood. Karin just happens to be one herself. Her family never really catches on that this "un-vampire" who is capable of living out in sunlight, eat normal foods, and creates blood instead of consumes is actually The Chosen One who can restore fertility among vampires by sharing her own blood.
- In Trinity Blood only people carrying a certain gene are susceptible to the Martian bacterium that turns humans into vampires (or Methuselahs as they prefer to be called). Most Methuselahs are born to vampire parents. And only Artificial Humans like the Nightroads can survive the Crusnik Nano Machines.
- In Shiki, some humans become vampires after being sucked out while others are not. The exact causes are not known, but it is speculated that it may have genetic causes. For a human can not become a vampire if at least one of his parents can not become one. The real goal, however, is to become a jinrou, but only very few humans can do that.
- It isn't explicitly stated, but the circumstances of Cassidy's vampirisation combined with the events of the Blood and Roses miniseries suggest that you become a vampire in Preacher by being bitten by a vampire and surviving, in a disease model. Vampires are rare because they generally go into a feeding frenzy when they bite people, and only fail to drain them to death if something interrupts them.
- In 30 Days of Night, every human who are bitten by a vampire will be turned in to one, too. Even if he is not killed. Because of this, the vampires almost always behead or burn their victims to avoid creating new vampires. But they do not seem to be very careful, because in the course of the movie at least four humans turn into vampires.
- Daybreakers: The Aversion of this trope is the entire basis of the plot. When vampirism first emerged, the vampires bred explosively, and ten years later the vampires outnumber the humans easily twenty to one... and are starving to death as a result, since they can't feed off each other without going insane.
- The Vampire Chronicles by Anne Rice popularized this version. In Interview With the Vampire the process is described as the human and vampire sucking each other's blood.
- Bram Stoker's Dracula is ambiguous as to whether it works this way. The Count forces Mina to drink his blood, forming a mental link between them, but he's not shown doing this to any of the other women he turned. On the other hand none of the ship's crew he ate rose as vampires.
- In The Saga of Darren Shan a vampire cuts the tips of his fingers and his new "assistant's" fingers and presses their cuts together so that their blood mingles. Notably the process has to be done at least twice, the first time only converts them into a Dhampyr.
- In The Sanguine Chronicles vampirism and lycanthropy are caused by two strains of a virus that most people are immune to. If you're not immune and are attacked by a vampire or werewolf you tend to get infected. Marko is the result of his mother getting caught in the middle of a Fur Against Fang fight while pregnant with him.
- In the Night Watch series, vampires are Dark Others whose creation is regulated by the Treaty. As such, each vampire must receive explicit permission from the Night Watch to turn a human, otherwise the Night Watch has a free reign under the Treaty to hunt down and to destroy both the progenitor and the progeny.
- In Morganville Vampires, during the early years of vampires, vampire numbers almost overwhelmed the human population due to their ability to transform humans into vampires rapidly as well as the human population being smaller than it was today. In order to prevent the humans running out and hence endangering the vampire's food supply, it was agreed by the higher vampires of the time to remove the knowledge of how to create more vampires, simply by refusing to teach it. Over time, this knowledge became lost even to the elder vampires resulting in it only being available from two sources, these being the world's oldest vampire, Amelie as well as an ancient spell book where it was written down.
- In Team Human the vampire population is kept down by three factors: The vampire has to completely drain a human to make a new vampire. It is against both human and vampire law for a vampire to turn a human into a vampire without that human's permission (and most vampires are law-abiding). Sometimes the attempt to turn a human fails, and a mindless zombie is produced instead.
- In Evernight, only people who have been bitten multiple times before by a vampire can themselves become vampires, and even then this is only true if the last bite is fatal.
- In My Vampire Older Sister and Zombie Little Sister, a vampire can only transform a human into another vampire by sucking a lethal amount of blood. Additionally, they form organisations to track the humans that they feed on in order to control the creation of new vampires.
- The Dresden Files has a Vampire Variety Pack:
- The Black Court are the classical Draculas, except they appear to be corpses in varying stages of decay. (Dracula was a treatise on the Court's strengths, weaknesses, and how to hunt them disguised as a novel, commissioned from Bram Stoker by their rivals in the White Court.) The Black Court is acknowledged to be the most explosive breeders, their victims getting right back up immediately, but their numbers are thinned by vampire hunters and other rivals, making them the most rare.
- The now extinct Red Court were basically humanoid bat monsters, capable of developing a second skin to disguise themselves as human. A bite survivor would become a half-vampire with a human appearance, the benefits of which include agelessness and strength, but would incur a strong blood thirst. When a half-vampire kills another person for their blood, they then transform into a full Red Court vampire. The Red Court was known to be the most populous Court, considering the relative ease with which they breed and their fairly low profile.
- White Court vampires are people with a demonic symbiote called a Hunger that turns them into succubi and incubi that can invoke and feed on emotions, the head family preferring a diet of lust. They reproduce sexually, producing human offspring with an embryonic Hunger attached. When the child of a White Court vampire loses their virginity, the Hunger awakens and kills their partner by draining them and turning the child into a full vampire. Notably, all White Court children come from male vampires, and the females appear to be sterile.
- There are other vampire courts, the biggest being the secretive Jade Court in East Asia, but they're too small or secretive for concrete information on them.
- Vampires in The Parasol Protectorate have their spread limited by a number of factors. Like their werewolf counterparts, they can only turn certain individuals with excess soul, which cant be reliably predicted. In addition, they have a psychic tether to their homes that will drive them insane if they stray too far from the hive, and only the rarer female vampires are capable of inducing the change.
- It's explained in The Dragon's Heir, the second book of the Nyctophobia series, that vampires create new vampires by spiting their own blood into the feeding wound. Without a cure, the infected human dies within two days then rises as a vampire. Female vampires are infertile, being physically dead, so Dhampyrs or "Living Vampires" are born from the union of a male vampire and a human woman. The process always kills the woman and usually yields stillborns. Princess Elisabeta, the titular heir, was a rare successful birth thanks to her father Dracula's countermeasures.
- The Mortal Instruments has a very complex ritual to turn a human into a vampire. At first, they must not suck him completely, and then he has to drink the blood of a vampire. Shortly thereafter, this human must be buried in holy ground. And even then, not every newly-transformed vampire is strong enough to free himself from his grave.
- The book series The Saga of the Noble Dead shows that some humans are sucked out, then become vampires, and other humans are not. But that depends on chance.
- In The Coldest Girl in Coldtown, vampirism is a virus which spreads through biting. Infected people are referred to as having "gone cold". It can take up to sixty-eight days to heal from the time of being bitten, but a person will only become a vampire if during these sixty-eight days, the person consumes human blood before the infection is out of their system.
- In Twilight, any living victim with vampire venom in their system will transform, but most people-eating vampires don't have the willpower to stop before the victim is dead, and the venom will just kill animals no mattter what.
- Night World: Vampires can only create other vampires by repeatedly exchanging blood with a human (or witch) - they drink the human's blood, then let them drink some of their own. If they don't get the balance exactly right, then the human can just die, or turn into a ghoul. It's further established that most people older than their teens cannot physically handle the transformation and their bodies will just "burn out". The Elder Council have also placed a ban on making just any human into a vampire, partly because turning someone requires you to break cardinal law no. 1: Never tell a human about the Night World. This actually drives some of the conflict in Secret Vampire, as James turned Poppy illegally, knowing he'd never get permission because he broke cardinal law no. 2: Never fall in love with a human. Lamia vampires can procreate the old-fashioned way, but made vampires are infertile.
- Buffy the Vampire Slayer:
- It establishes this in the first episode when Buffy explains to Giles why the first victim we see won't return as a vampire.
Buffy: To make you a vampire, they have to suck your blood. And then you have to suck their blood. It's like a whole, big, sucking thing. Mostly, they're just gonna kill you.
- In addition, vampires are normally possessed by demons upon siring. After Buffy destroys the Seed of Wonder that allowed demons to enter the world attempts to sire vampires produce mindless "zompires".
- It establishes this in the first episode when Buffy explains to Giles why the first victim we see won't return as a vampire.
- In Preacher, vampires are able to turn normal humans into vampires easily enough, but the vampire population is limited because the race has a terrible epidemic of Chronic Backstabbing Disorder that drives them to attack and kill each other.
- My Babysitter's a Vampire: Humans bitten by vampires will typically become vampires themselves, however there are two ways of getting around this; a fledgling vampire that does not drink blood will die in 28 days if they can't find a blood substitute to sustain them, while also not having all their abilities. A human who has the vemon drained from their blood before transformation will be spared from transforming at all.
- True Blood also does the "drain, then feed" technique, with the added limiter that newly created vampires have to spend one night in the grave with their maker for the whole process to take.
- Contagious vampires are actually rare in the assorted folklore that inspired them. In most cases they spontaneously arose from a corpse that died under certain circumstances, such as suicide.
- Romanian strigoi actually reproduced sexually, mating with humans to produce Dhampyrs who became strigoi when they died.
- Vampire: The Masquerade and its successor Vampire: The Requiem:
- Vampires reproduce by exsanguinating a human to the brink of death, then feeding them a few drops of vampire "vitae" and making a huge effort of will to revive them. The games represent this differently: in Masquerade, siring requires the expenditure of a Willpower point, meaning mass creation of vampires is a possible tactic. In Requiem, creating a full-fledged vampire requires burning a Willpower dot, which can only be bought back in time; trying to create a vampire by just spending a Willpower point will create a feral half-vampire. Feeding vitae to a healthy human temporarily empowers them as a Ghoul instead.
- Masquerade also ranks vampires by "generation", i.e. how far removed from their antediluvian vampire progenitors they are. Most Player Characters start between 10th and 12th generation; 13th generation vampires only have a 50% chance of being able to sire useful offspring, who are usually "thin-blooded" with weakened powers.
- In Masquerade, there's also an artificial limit in some cases. In the cities of the Camarilla, the Prince, the highest authority, is the only one who can award vampires the right to sire. Anyone who tries making a kid without their blessing will face punishment, possibly destruction; this might also fall on the kid, too.
- Dungeons & Dragons 3rd Edition: A humanoid with four or fewer Character Levels or Hit Dice doesn't become a vampire if drained of blood by one; instead, they rise as a less-powerful "Vampire Spawn" that can't turn people.
- Magic: The Gathering acknowledges in-story that between their decadent feeding habits and competition from many other man-eating horrors, the vampires of Innistrad would have run out of humans to eat long ago and consequently starved to extinction. Seeing this, the planeswalking vampire Sorin introduced a conservation program of sorts in the form of Archangel Avacyn to give humanity a fighting chance. This wasnt exactly appreciated by his kin, and now that shes dead its anyones guess what will happen.
- In the Zendikar setting, only the bloodlords are able to produce new vampires. If their "children" try to, they just end up with mindless zombies called nulls.
- In Warhammer, making a new vampire requires secret elixirs based on Neferata's research (and Neferata herself became the first vampire by trying to make an immortality elixir from studying Nagash's scrolls).
- In Ironclaw vampires, or "oupires", aren't contagious, they're produced by necromancy or bargains with dark powers.
- Vampires in Urban Jungle are produced when an occultist allows a malevolent spirit to possess him. Victims of their feeding are essentially zombies that drink blood.
- The Elder Scrolls series treats vampires as being Deceased and Diseased, but being attacked by a vampire does not guarantee being infected, and the disease takes about three days to completely transform the infected into a vampire, giving those who don't want to transform a reasonable amount of time to seek a cure.
- Town of Salem has vampires as a a potential in-game faction. There can only be a maximum of 4 vampires (out of a starting total of 7-15 players. They are also limited in that they can only turn town members into vampires... biting a Mafia member kills them, and other hostile factions are immune to vampirization.
- In Heroes Of Might And Magic Ashan, the process of creating a vampire involves gradually replacing a human's blood with venom milked from namtaru spiders. Because many necromancers are deeply religious and consider namtarus sacred creatures of the goddess Asha, vampirism is considered a reward for a lifetime of service to the necromancer's cause, and is almost exclusively offered to very old necromancers.
- In Tsukihime, vampires who suck a human's blood can then inject them with some of their own blood to turn them into the Dead (a zombie, for all intents and purposes). In some cases, however, exceptional victims don't die completely, but instead turn into beastly ghouls. By consuming human flesh for many years, ghouls can eventually regain their human intelligence, completing their transformation into a vampire, — but only a few actually manage to survive that long, putting an additional limit on new vampire population. And in even more extraordinary cases (as seen with Satsuki), it's possible for one to immediately become a full vampire. It's also possible for a human mage to use their magecraft to create vampires without the participation of an existing vampire, but this also usually just creates ghouls.
- Sluggy Freelance has a Vampire Variety Pack of at least three with different reproductive methods.
- Vorpyr are produced through a three night ritual of slow draining of blood and feeding small amounts of blood from their circle's Vampire Monarch. By the time they're introduced they've been reduced to a single circle which is trying to rebuild their numbers, which is then wiped out by the protagonists save for their friend Sam and one other they staked and forgot to finish off.
- Vrykolakas turn everyone they kill, but the majority of them are weak, turning to dust if staked with a toothpick or their sire is destroyed. When their queen and ultimate progenitor is killed almost the entire species is dusted, save for some stronger individuals who are merely weakened.
- The Strakoi's means of procreation haven't been brought up yet.
- Played with in The Order of the Stick, where creating a new vampire usually requires an existing vampire to kill someone by completely draining their blood and leaving them in their grave for 3 days. However, particularly powerful vampires have ways to speed up the process; for example, the staff carried by minister Malack has a spell stored in it that can instantly resurrect his victims as vampires.
- Weirdly averted by this (apparently Twitter-original) Micro Flash Fiction:
"Hello! Do you have a minute to talk about Dracula?"
"No— wait, Dracula?"
"Yes. We have pamphlets."
"Vampires have missionaries?"
"Where else would new vampires come from?"
"I assumed you bit people."
"There are many hurtful stereotypes. May we come in?"
- School For Vampires: Vampires in this series mostly produce sexually, so like humans they are born as babies and grow up from there. It is possible for vampires to turn humans into vampires, but only if they bite them during a full moon. And the process can be reversed by giving the victim a blood transfusion.