Be More Chill is a musical with original music and lyrics by Joe Iconis, and a book by Joe Tracz, based on the 2004 novel of the same name by Ned Vizzini. After a 2015 regional theatre production, the musical premiered off-Broadway in 2018. A Broadway production began previews on February 13, 2019, and officially opened on March 10, 2019. The Broadway production closed on August 11, 2019. An off West End production opened on February 18, 2020, and temporarily closed on March 16, 2020, due to the ongoing COVID-19 pandemic with the production being cancelled on June 3, 2020. In 2021, it was announced that the production, featuring the original London cast, would resume performances on the West End at the Shaftesbury Theatre for a 10-week run starting June 30.

As of 2018, a film adaptation is in development.

Productions New Jersey (2015) The musical premiered on May 30, 2015, at the Two River Theater in Red Bank, New Jersey."Current Season" tworivertheater.org It ran until June 28, 2015. The production was directed by Stephen Brackett and featured orchestrations by Charlie Rosen, music direction by Nathan Dame, and choreography by Chase Brock. It featured Will Connolly as Jeremy, Eric William Morris as The SQUIP (an acronym for "Super Quantum Unit Intel Processor"), George Salazar as Michael, and Stephanie Hsu as Christine, as well as Katie Ladner, Lauren Marcus, Jake Boyd, Gerard Canonico, Katlyn Carlson, and Paul Whitty. The musical was commissioned by Two River Theater in 2011 as part of their new play development program.

Off-Broadway (2018) After mixed reviews in its out of town tryouts, the show did not receive another production. In early 2017, the show began to gain traction online. A cast recording of the original production entered Billboard Cast Album chart's Top 10 in July 2017. This accomplishment and its workshop success led to the show getting an Off-Broadway production in 2018.

Be More Chill ran Off-Broadway at the Irene Diamond Stage at the Pershing Square Signature Center. It began previews July 26, 2018, officially opening on August 9, 2018. It was originally scheduled to close on September 23, 2018, but was given a one-week extension after selling out and closed on September 30, 2018.McPhee, Ryan. "Be More Chill Will Play Off-Broadway; Will Roland to Star", Playbill.com, April 13, 2018 This production featured several original cast members including Hsu, Salazar, Canonico, Carlson, and Marcus reprising their respective roles. New cast members included Will Roland as Jeremy, Jason Tam as the SQUIP, Britton Smith as Jake, Tiffany Mann as Jenna, and Jason "Sweettooth" Williams as Mr. Heere, and all other adult roles. The production also added Emily Marshall as music director.

Broadway (2019) On September 5, 2018, a Broadway production was announced. Preview performances at the Lyceum Theatre began on February 13, 2019, and the show officially opened on March 10, 2019. The Broadway transfer was estimated to cost $9.5 million according to lead producer Jerry Goehring. On December 18, 2018, it was announced that the entire Off-Broadway cast would reprise their roles for the Broadway production. Understudies and covers for the Broadway production featured Cameron Bond, Anthony Chatmon II, Morgan Siobhan Green, Troy Iwata, Talia Suskauer, and Joel Waggoner. Both the Broadway and Off-Broadway productions were represented by long-time Broadway press agency, Keith Sherman & Associates. The production announced its closing on June 20, 2019, and closed on August 11, 2019, playing 30 previews and 177 performances.

Off-West End (2020) Be More Chill announced a London run on September 29, 2019. Previews began at The Other Palace on February 12, 2020, with an opening night set for February 18, 2020. On December 9, 2019, casting for the London production was announced, with Scott Folan as Jeremy, Blake Patrick Anderson as Michael, Miracle Chance as Christine, and Stewart Clarke as the SQUIP. Other cast members included Renée Lamb, Millie O'Connell, Eloise Davies, James Hameed, Miles Paloma, and Christopher Fry. The set was changed from the Broadway set, with an LED screen being the main feature for backgrounds, and fewer physical set pieces. Although the production was scheduled to close on June 14, 2020, it was announced on June 3 that all remaining performances of the show would be cancelled following its early closure on March 16, 2020, due to the COVID-19 pandemic.

Cancelled Chicago production (2020) On December 12, 2019, the show announced that it would open an 18-week limited engagement run in Chicago at the Apollo Theater. Previews were set to begin April 17, 2020, with an opening night set for April 26, 2020. However, because of the COVID-19 pandemic, the show's previews were postponed to July 7, 2020, and the opening night was moved to July 17, 2020. The cast was announced as Liam Oh as Jeremy, Jeremiah Alsop as Michael, Rebecca Hurd as Christine, Teresa LaGamba as Jenna, Michelle Lauto as Chloe, Eben K. Logan as Brooke, Billy Rude as Jake, Koray Tarhan as Rich, Alex Goodrich as Mr. Heere/Mr. Reyes, and an unannounced SQUIP. Due to challenges caused by the COVID-19 pandemic, Be More Chill announced that the production at the Apollo Theater has been cancelled.

West End (2021) On May 14, 2021, it was announced that the production would transfer to London's West End, resuming performances at the Shaftesbury Theatre for a 10-week run, with most of the original London cast reprising their roles. Millie O'Connell and Renée Lamb would not reprise their roles as Chloe and Jenna, and would be replaced by Grace Mouat and Nathania Ong. The show opened on June 30 and closed on September 5, 2021.

Japanese production (2022) On July 25, 2022, Be More Chill Japan began performances at the New National Theatre Playhouse in Tokyo, containing the same set design and script from London. After wrapping August 10, the show continued to run in Fukuoka and Osaka. The cast consisted of Kota Yabu, Seishiro Kato, Sayuri Inoue, Yuya Kido, Akiyoshi Utsumi, Ruki Saito, Marika Dandoy, Ayaka Larrison, Bro Tom, and Daisuke Yokoyama

Plot Act One Jeremy Heere, a high school junior, is a social outcast. He lives with his recently separated father, who works from home and makes Jeremy uncomfortable by repeatedly refusing to wear pants in the house. At school, Jeremy is bullied by popular student Rich Goranski. His best friend, Michael Mell, also bullied by Rich, tries to comfort Jeremy by telling him that being a loser is okay. Jeremy's long-time crush Christine Canigula signs up for the school play, which prompts him to do so as well, despite being made fun of for it. Jeremy wonders if someone can help him to become popular ("More Than Survive"). As they wait for the first play rehearsal to begin, Christine professes her love and passion for theatre to Jeremy ("I Love Play Rehearsal"). The drama teacher, Mr. Reyes, reveals that the school play will be A Midsummer Night's Dream set in a post-apocalyptic future, re-titled A Midsummer Nightmare (About Zombies). During rehearsal, Jake Dillinger, one of the popular boys, flirts with Christine, making Jeremy jealous ("More Than Survive (Reprise)").

Later, Jeremy is tormented in the bathroom by Rich, who tells Jeremy how he managed his rise to popularity: as an unpopular freshman, he took a pill called a Super Quantum Unit Intel Processor (SQUIP) containing a computer that implants itself inside the user's brain and tells the user what to do and say. Taking pity on Jeremy, Rich suggests that he buy one in order to become cooler ("The SQUIP Song"). After school, while playing video games with Michael, Jeremy tells him about Rich's offer and considers if Rich is just scamming him. After an awkward conversation with his dad, Jeremy decides to check the SQUIP out. Jeremy assures Michael that, no matter what happens, they'll always be a team ("Two-Player Game").

The two visit the mall to buy the SQUIP from a dealer at Payless ShoeSource. Jeremy, as instructed, swallows it with green Mountain Dew. When the SQUIP activates, it causes Jeremy to panic in front of Christine and Jake ("The Squip Enters"). The SQUIP criticizes Jeremy's appearance, personality, and behavior, and tells him that everything about him is terrible ("Be More Chill, Pt. 1"). The SQUIP orders him to go to a store to buy a new Eminem shirt. When Jeremy picks up a woman's shirt and encounters two popular girls from school, Brooke Lohst and Chloe Valentine, the SQUIP helps Jeremy fabricate a story in order to connect with them both. They offer Jeremy a ride home ("Do You Wanna Ride?"), which the SQUIP demands he accept, but Jeremy declines because he does not wish to leave Michael in the mall. The girls leave, and the SQUIP lies to Jeremy, telling him that Michael has already left the mall. It tells him that in order for its plan to improve his social standing to work, Jeremy needs to obey every order it gives him ("Be More Chill, Pt. 2").

The next day, Jeremy heads to school with renewed confidence, wondering if he might be less invisible than before. The SQUIP delves into the inner psyche of the student body around him, giving Jeremy insight on the fears and insecurities of his peers. Jeremy's SQUIP syncs itself with Rich's, instantly making them friends. Jeremy heads confidently to the play rehearsal ("Sync Up"). Christine tells Jeremy about her feelings for a guy she knows, who Jeremy initially believes is himself, but who turns out to be Jake ("A Guy That I'd Kinda Be Into").

Afterward, the SQUIP informs Jeremy that Christine won't date him until his social standing drastically improves and encourages Jeremy to use an interested Brooke as a stepping stone to greater popularity. Jeremy starts a relationship with Brooke, while Jake asks Christine to come to his house ("Upgrade"). Overwhelmed, Jeremy asks the SQUIP to shut itself off for a few minutes. Immediately, Jeremy sees Michael and is elated but Michael states that Jeremy has been ignoring him all day. The SQUIP explains that it was using optic nerve blocking to block Michael from Jeremy's vision and that he has to abandon him in order to be more popular. Jeremy, deciding he is tired of being a loser, turns the optic nerve blocking back on, and leaves Michael as the SQUIP plots to further boost Jeremy's popularity ("Loser Geek Whatever").

Act Two On Halloween, Jake hosts a large, unsupervised party featuring alcohol ("Halloween"). Christine arrives in her Juliet princess costume because of Jake's past compliment on it, hoping to please Jake, but he brushes her aside to party. Jeremy arrives to meet Brooke, but Chloe, who is jealous of her, tries to seduce Jeremy. Feeling uncomfortable, Jeremy tries to get away, but the SQUIP forces him to remain in the situation as it escalates to Chloe making out with Jeremy ("Do You Wanna Hang?"). Chloe also has Jeremy drink alcohol, causing the SQUIP to malfunction, and then feigns having sex with him after being caught, angering Jake and upsetting Brooke. Fleeing from Jake and the girls, Jeremy runs into a bathroom, where he finds Michael, who has crashed the party. Michael tries to warn Jeremy of the dangers of the SQUIP, having discovered that someone ended up in a mental hospital after going insane in trying to get rid of it. Jeremy accuses Michael of being jealous of his popularity and calls him a loser, storming out of the bathroom. Michael, devastated and angry, locks himself in the bathroom and experiences a panic attack as he mourns the loss of his only best friend ("Michael in the Bathroom"). Jeremy talks to Christine without the SQUIP's help and he asks her out in a burst of confidence ("A Guy That I'd Kinda Be Into (Reprise)"). Christine, who has found herself in an existential crisis after breaking up with Jake, declines.