Due to her position as a queen bee of Rosewood's social scene, Alison's actions and relations were constantly under scrutiny from the town's citizens.

Sasha Pieterse, who portrays Alison on screen, has described the character as an indecisive person, showing herself as a ruthless, manipulative girl.

[2] Due to the massive reformulation on the story's timing, pacing and overall narrative for the television adaptation, the on-screen Alison DiLaurentis holds various differences from her literary counterpart, such as the fact that the latter has an identical twin sister, while the former does not.

The twin sisters Alison and Courtney Day-DiLaurentis were born on June 6, 1990,[citation needed] the fruits of a secret sexual relationship between Jessica DiLaurentis and Peter Hastings.

[5] Soon, Alison took the stalking method and began to chase the girls, seeking revenge for them being outside that day that Courtney used them to trick her mother into believing that she were her sister.

The DiLaurentis revealed the secret about the twins after a man named Billy Ford was arrested for murdering Alison, saying that they kept the sisters hidden for so long to avoid turmoil in town.

[7] Nick stayed with her during her healing process, but Alison eventually discarded and incriminated him for everything she had committed, such as the homicides of Ian Thomas and Jenna Cavanaugh.

In order to finally get her revenge, Alison wrote an entire diary with untrue stories of the girls torturing her while they were keeping her hostage.

[12] After the reveal of Alison's fate in the ending of season 4, Pieterse confirmed that DiLaurentis' personality had drastically changed; she has to "figure out who she is.

[13] Alison DiLaurentis is introduced as a very popular girl from the suburb of Rosewood, Pennsylvania, and the leader of a clique composed by her, Spencer Hastings, Aria Montgomery, Emily Fields and Hanna Marin.

The first minutes of the pilot episode show the five friends reunited in the barn-turned-loft of the Hastings family during a night of summer vacation.

In the midst of night, Hanna, Emily and Aria wake up to see Spencer arriving back to the barn after leaving to somewhere.

[15] Days after, through Spencer's sister Melissa Hastings, the girls find Thomas' dead body, accompanied by a suicide letter in which he admits that he killed Alison.

[31] With this confirmation, the girls start a quest to find Alison, following the steps of two persons using the Red Coat costume, one of them being revealed to be CeCe.

When Shana Fring is killed by Aria Montgomery after being revealed as "A" and turning on Ali and the girls, Alison returns home to Rosewood after and reports to the cops.

While the girls were in New York, back in Rosewood Jessica DiLaurentis (Alison's mother) was killed and buried in the Hastings backyard.

Alison comes up with a plan with Ezra Fitz, Toby Cavanaugh, and Caleb Rivers to find the girls and make sure they come home soon.

Alison is a teacher at Rosewood High School and is engaged to one Archer Dunhill, then known as Elliot Rollins, who was Charlotte DiLaurentis' doctor during her five years at Welby.

Alison is admitted to a psychiatric hospital due to being tricked by Mary Drake and Archer in Jessica DiLaurentis and Darren Wilden costumes, thinking that she was seeing their ghosts.

[39] She discovered that she was in fact impregnated at Whelby by A.D.[40] with Emily's eggs and a then unknown man (Wren Kingston[41])'s sperm, during her turn at the "Liars' Lament" board game.

[46] After receiving a divorce paper from her wife, Alison decides to investigate the death of Taylor Hotchkiss who allegedly committed suicide a year ago.

[47] After finding and convincing Taylor to return, Alison and the group continue to deal with Dana Booker, the head security of BHU who is investigating Nolan's death.

[48] After Dana exposed their secrets, Alison and Dylan are expelled from BHU, Mona is fired, while Caitlin and Ava had to leave.

[49] However, after Caitlin's boyfriend Jeremy is accused of the murder and is shot by Taylor, Claire apologized to the group and allowed them to stay.

In earlier seasons and when appearing in flashbacks, Alison was praised as a pivotal character to the plot of the series despite being presumed deceased.

Aya Tsintziras of Screen Rant praised her character for her large impact on the show, and "[continuing] to make fans wonder what's going on".

[52] Alternatively, Pieterse's character is berated for displaying the latter on her close friends and family, and seemingly feeling remorseless for her wrondoings, being referred to as "a mean girl who [makes] Regina George look sweet".

The reveal itself was generally praised for being a dramatic twist, with many viewers becoming excited to see the character alive and interacting with the other Liars in real time.

[54][55] Following the events of "'A' Is for Answers", Autumne Montague of TVOvermind lauded Pieterse's character for her self-awareness in having admitted not being a good friend, calling the moment "refreshing from a girl who in flashbacks seemed simply self-absorbed.

In Seasons 6 and 7 in particular, many fans felt that her dynamic changing from self-serving "mean girl" to codependent and empathetic, albeit partly due to the trauma of her time away from Rosewood, was unrealistic and poorly written.