Early concept art/designs of Lilith, who was originally supposed to be half angel and half demon, and was originally Morrigan's biological, older sister, before eventually being changed into just a split soul fragment of her.
- Capcom's original intention was to make a licensed fighting game starring monsters from the Universal Horror franchise, but the deal fell through. The initial premise can still be glimpsed in certain characters who were obviously modeled after Universal monsters (Demitri = Dracula, Jon Talbain = The Wolfman, Victor von Gerdenheim = Frankenstein's Monster, Rikuo = The Creature from the Black Lagoon, and so on).
- Rejected monster ideas included a nurikabe that would've constantly been in guard mode, and a takeoff on The Invisible Man who would've only been identified by a pair of gloves that'd be floating on the screen.
- There were plans for a fourth title in development for the CPS-III system. It is said that Vampire Ace (or Vampire Soldier as it's been called in some places) would have had the core gameplay of Vampire Savior with CPS-III fluid characters. The reasons for the cancellation are unknown.
- Every character's final design and story is a far cry from the original intention:
- Demitri had a much more minimalist, agile-looking design.
- According to the Darkstalkers Graphic File, Morrigan was originally going to be the "cute" character of the series, while all of the sex appeal would go to Felicia.
- One of Morrigan's preliminary character designs eventually became Jedah, which is probably where they got the preliminary sibling relation from.
- Lord Raptor was supposed to be a vengeful zombie soldier from WWI, hence his birthdate being stated to be in the 1800's—they forgot to change it to reflect the metal image.
- Bishamon himself was going to be possessed and not wear any armor.
- Rikuo looked "like something straight out of the Cthulhu Mythos".
- Anakaris was a slender pyramid guardian.
- John Talbain looked more man than wolf and had extremely long claws on one hand.
- Sasquatch was an animalistic brute bound in chains.
- Victor was a complete lift of Karloff's Monster before being modified into a robot.
- Huitzil was a much more modern robot designed for labor. He also had an unfinished super in the first game that was abandoned and never brought back in any of the sequels.
- Pyron's looks varied too wildly to do justice in such a small space as this.
- Donovan underwent through a large amount of changes:
- He was originally a stereotypical Caucasian Vampire Hunter with a broad-brimmed hat that covered his eyes, resembling a masculine Vampire Hunter D or Van Helsing. As designs changed some Asian martial artist themes were added with braided hair and a nunchaku like weapon. Finally we were given the Hinduism/Buddhism themed dhamphyr.
- He was also much stronger in the location test build of Vampire Hunter than he was in the finished product. Some of his strengths that were lost include a completely different Blizzard Sword special that caused his ice-covered sword to come crashing down from the top of the screen, a Kill Shred special which had his sword spinning through the air vertically rather than horizontally, thus covering a much wider area, and a Change Immortal EX that would cause huge amounts of chip damage when blocked.
- Hsien-Ko's design, though consistent throughout the games, was originally going to be much younger.
- In the early stages of development, Lilith was Morrigan's older sister who had the blood of angels mixed in her. She physically resembled Morrigan, the only exception being a pair of angel wings on her head that she hid out of embarrassment.
- Q-Bee was a mutated insect with command over other bugs.
- Early in development, Jedah was an angelic bishie called "Belial, Jr.", which would have made him Morrigan's adoptive brother.
- Some rough animation concepts shown in Darkstalkers Official Complete Works give insight into ideas for moves that didn't make the cut. An anchor could have been among the many weapons Hsien-Ko produces from her sleeves, Huitzil's Confusioner could have involved him summoning a large radio-controlled drone with a grabber claw, and Demitri's Demon Billion seemingly could have been a utility super that allowed him to perform different moves while transformed into a cloud of bats, including jabs, uppercuts, and converging bites.
- The first game was planned to be ported to the Sega 32X.
- Marvel vs. Capcom 2 original character Ruby Heart was originally conceived as a character for Darkstalkers. Ditto the new character Amingo, although no one is really sure either way.
- The "Darkstalkers Are Not Dead" teaser, which was never followed up on after the poor sales of Darkstalkers Resurrection. Then producer of Street Fighter Yoshinori Ono confirmed, after leaving the company, that was an attempt to convince Capcom to produce a new game.
- Much of the cast from this series were considered for the roster of Marvel vs. Capcom 3 (specific ones include Talbain and Donovan, the former being Ryota Niitsuma's personal choice for a fourth Darkstalkers character). Only Morrigan, Felicia, and Hsien-Ko were included in the final game, though at the very least Amaterasu got a Talbain-themed alternate costume and many of the characters appeared as cards in the Ultimate update's Heroes and Heralds mode.
- After the success of their Street Fighter toys, SOTA announced plans to produce a Darkstalkers action figure line. Prototypes for figures of Morrigan, Lillith, Demitri, Anakaris, Donovan, Lord Raptor and Jedah were produced, but the line never officially made it into production.
- In 2011, UDON (the makers of the American Street Fighter comics) pitched an HD update of Darkstalkers in the vein of their hit Super Street Fighter 2 HD Remix, which would have featured newly redrawn sprites. The proposal was rejected, but the prototype Morrigan sprite later found its way online
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