Spencer is known in the fictional town of Rosewood for her sophisticated charm, intelligence, hardheadedness, and, at times, dangerous dedication to achieve her life goals.

She is part of the very wealthy, powerful Hastings family; Spencer's parents, Veronica and Peter, are both linked to politics and her sister, Melissa is an almost-equally accomplished grad student.

She is known to have a dark side and suffers from rage-induced black outs, which leads her to question whether she had anything to do with the death of her friend Alison.

In later books, Spencer is briefly addicted to drugs, which she takes to help her improve her grades at a University of Pennsylvania summer school.

Troian Bellisario was cast as Spencer Hastings for the Pretty Little Liars television series adaptation in November 2009.

[4] Spencer is similar to her book counterpart: she is portrayed as a highly ambitious, intelligent young woman from a wealthy family who frequently competes with her older sister Melissa for accolades and the approval of their parents.

Spencer is on the Rosewood Day field hockey team, and plays tennis at her family's country club.

[7] Spencer then dates Alex Santiago after they met at her family's country club[8] but A sabotages their relationship and the two break up.

Spencer is initially suspicious of Toby Cavanaugh's role in Alison's death and they begin a friendly relationship in the second half of the first season, which eventually becomes romantic[9] Their relationship is stable until A threatens Toby's life to Spencer and she decided to end things to keep him safe.

She eventually learns that Toby is still alive and he explains that he was working with A as a double-agent and faked his death but his allegiance was always with Spencer and The Liars.

Spencer wants to use his police resources to find "A" while Toby prefer to maintain a separate work/life balance, causing the two to break up again.

Spencer then begins a flirtation with Jonny Raymond, an artist renting out the Hastings' guest house.

[20][21] Spencer Hastings is a preppy, ambitious, and competitive student who strives for perfection due to her parents' high expectations.

Alex confides in Spencer that he had received an invitation to a prestigious tennis clinic but was uninterested in pursuing it.

But after the two spend time together in a motel room in the episode "Person of Interest", the two begin a romantic relationship.

The two have a tense relationship and Ian successfully convinces the Hastings family that Spencer's erratic behavior is due to jealousy of him and Melissa.

While doing yard work for the Hastings, Toby digs up Spencer's old field hockey stick which she gave to Alison before she died.

Spencer becomes suspicious and after doing some further investigating, she reads Alison's autopsy results and finds that she was struck in the head with an object similar to a field hockey stick.

She discovers that Peter did something illegal for the DiLaurentis family and worries that her father covered up her involvement in Alison's murder.

Summer has passed since the unveiling of A but Spencer is determined to uncover the Black Swan, whom she believes is another A still working with Mona.

In the Season 3 finale "A Dangerous GAme", Spencer comes up with a plan to trap the Red Coat and reveals to the Liars that she is working for the A-Team as a double agent.

As part of the plan, Spencer hosts a party at a lodge where the girls are supposed to meet the Red Coat, when an unknown figure starts a fire, trapping Aria, Hanna, Emily, and Mona in the burning house.

The Red Coat rescues the Liars from the burning house and Hanna and Mona also believe to have seen Alison.

In the episode "Grave New World" the Liars learn that A believe Alison will be returning to Ravenswood on the night of the graveyard party.

Following this, Spencer tries even harder to work out who A is in order to make it safe for Alison to come home.

She returns to Rosewood five years later at Alison's request, and also to depose on Charlotte's release from psychological hospital.

It is revealed that during the five last years she and Toby broke up because of the distance and the different future plans, and, following, she started a thrilling flirt with Caleb Rivers.

Having to stay in Rosewood after Charlotte was murdered, she starts working on her mother's election campaign for Senate, while the daughter of the other candidate is Yvonne Phillips, Toby's current girlfriend.

When a document about Yvonne's mother leaks and Caleb takes the blame, Spencer goes crazy, and Toby fights with him.

Spencer, along with the other Liars, Caleb, Mona and Toby, elaborate a plan to take "A.D." down, but everything goes down when the stalker kidnaps Hanna.