This trope is often used to criticize gender stereotypes such as the Madonna-Whore Complex, by introducing a Good Bad Girl and a Hypocrite as potential Love Interest for a guillible hero and teaching him not to judge a book by its cover. Other examples for the mere sake of suspense also exist.
Rarely leads to a Shocking Swerve. Indeed, most examples are The Untwist, but not in a bad way, and it is always a pleasure for the audience to see the heroine / hero fall in love with the Ensemble Darkhorse they wanted to win. However, if done well, it can create astonishment and chracter development and a sense of shared guilt with the center of the Triangle for misjuding the Love Interest.
Often a Subtrope of the trope Un ReQuited Love Switcheroo.
Anime and Manga
In the Princess Tutu anime, Fakir appears at first as a male Tsundere, and Mytho the Prince has a case of Chronic Hero Syndrome. They were respectively the Veronica and Betty to Ahiru's Archie Of course until Mytho's heart shard was tainted with the Crow's blood and he becomes evil and potentially violent, and Fakir is seen as the friend and confident who does everything he can to protect Ahiru.
In theArchie Comics, the Betty becomes a Veronica when she tries to murder Archie out of spite. For Veronica, despite having mistaken herself for a romantic novel heroine after a knock on the head, she never did such a thing, and thus gets the title of Betty in the trope namer for this kind of triangles.
Daniel Deronda may make this Older Than Radio. Mirah is jewish, an outcast with an artistic and melancholy disposition, Gwendolene is charming, well-liked and christian. Gwendolene is also too self-involved, though in an understandable and harmful way, while Mirah is sweet and innocent.
Moonlight has Kayla with Mason and Lucas. She sees Mason as a Nice Guy and Lucas as a less kind and harmless person. However, the readers can see from early on that Mason is a Manipulative Bastard who is insulting to his rival and tries to make Kayla drunk, while Lucas ignores him and is simply kind to her, but has intimidating manners. It must be acknowledged once Mason does a Face Heel Turn.
The The Summer I Turned Pretty trilogy by Jenny Han revolves around the heroine Belly's romances with the sons of her mother's best friend. In the beginning, Conrad was the aloof bad boy while Jeremiah was the Nice Guy. In the last book, Jeremiah has become a somewhat obnoxious frat boy who cheats on Belly. Meanwhile, Conrad is mature and studious (and also gets the girl at the end.) Belly only saw them on family vacations in the summer so she's unsure if they (especially Jeremiah) were always like that and she never saw it or if they actually changed.
The twist in Jim Carrey's The Mask. The mousy coworker is actually a spy for the villain, the seemingly exotic dame he met at a club is actually much more centered than she first appeared.
Live Action TV
Glee apparently has Rachel as Betty and Quinn as Veronica to Finn's Archie. This is subverted in the episode "Original Songs," when Quinn explains to Rachel that, however things might appear, she, Quinn, is actually the girl-next-door whom Finn will end up settling for, and Rachel is really the unattainable fantasy dream-girl.
In the BBC's Robin Hood series Marian had the choice between Robin and Guy, who were quickly revealed to be more than they first appeared. Guy is conservative and law-abiding (Betty) but also dangerous and a torturer (Veronica), whereas Robin was an outlaw and a thief (Veronica) but also Marian's childhood sweetheart, Robin Hood, and much more in love than he first appeared (Betty).
It can also be argued to happen between Isabella and Kate for Robin. The first may be the seductive artistocratic and morally ambiguous antagonist and Angry Sheriff's Beautiful Sister and Kate the Farm Girl who joined the outlaws, but Isabella is a Tragic Villain who tries to get rid of her rival by diminuishing Robin's trust in her... while the Farm Girl simply tries to kill the noble-born rival. Unlike Isabella, Kate didn't have the excuse of growing paranoid due to years of abuse by a sadistic husband, so the line is at least blurred.
In The Secret Circle, the live-action adaptation of the book series, Cassie initially appears to be a timid and shy Girl Next Door. For Diana, she is a confident and mature witch. As the series progresses, Cassie becomes more extroverted, ambitious, and willing to use her dark magic, but Diana grows more isolated and more cautious about the consequences of their actions. The point is driven home when Diana learns that she has dark magic as well. She makes it very clear that she will not be as reckless with it as Cassie is. This is in contrast to their initial characterizations, Cassie desiring to stay away from the circle, and Diana to embrace their birthright as witches. Adam's interests tend towards which girl is more The Veronica at any given time. He is initially dating Diana, (she is a Victorious Childhood Friend), they break up as the personality shift starts, and he starts dating Cassie a few episodes later.
It happened in True Blood, following Erik's amnesia (which ended up turning him into an Adult Child, and then into something closer from a Nice Guy) and Bill's acquisition of the title of King (which ended up making him a powerful authoritative villain). The first had Hair of Gold all along, and the second has brown hair from the beginning, so they both ended up filling their new function better than before.
It happened in the third series of The Vampire Diaries to Damon and Stefan (the former becomes more caring in some scenes, and tries to redeem himself in the eyes of his beloved, the latter gets his emotions switched off and becomes a villain).
The versions of the myth of the knight Pelleas (from the Arthurian legend) sometimes feature this. Pelleas falls in love with the lady Ettarde. She then pretends to reciprocate in order to have him win something for her in a tornament. She pushes him away when she has it, but he thinks it is all a test and comes to visit her every day. Growing annoyed, she puts him in her gaol and frees him every day. Pelleas then meets Gawain, who decides to help him by visiting Ettarde and later opening the gates, but Gawain falls in love with her, she reciprocates, and he does not follow his vow and Pelleas discovers it. Then, the different versions of the myth diverge :
A)Either Pelleas goes in his tent, becomes depressed, and is saved by a sweet, ethereal-looking Lady Of The Lake, Elaine, who reveals that she has very powerful magical powers (and a lot of Hidden Depths when she curses who she believes to be her rival, while Pelleas has fallen in love with herself and forgotten Ettarde), Ettarde finds out Gawain's original plan and, furious with him, regrets Pelleas.
B)... either Pelleas grows mad with rage, and becomes the Red Knight, devoted to prove the hypocrisy of Arthur's court.
In the backstory of Digital Devil Saga, Serph Sheffield appears to care for Sera, but in reality he's a Manipulative Bastard and regards her as little more than a tool for his own gain. Heat O'Brien genuinely cares for her in spite of his hostile exterior. Serph's murder of Heat causes Sera to realise the truth.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
Is that what you meant to do?
You are saying this draft has a ready-to-publish hat it does not deserve and you are taking it back.