The Conjugal Configuration

Series 12, Episode 1 Unrated CC HD CC SD

In the twelfth season premiere, Sheldon and Amy’s honeymoon runs aground in New York, while Penny and Leonard discover they are uncomfortably similar to Amy’s parents; Meanwhile Raj insults physicist NEIL DEGRASSE TYSON and starts a Twitter war. KATHY BATES and TELLER return as Amy’s parents.

The Wedding Gift Wormhole

Series 12, Episode 2 Unrated CC HD CC SD

Sheldon and Amy drive themselves crazy trying to figure out what “perfect gift” Leonard and Penny got them for their wedding. Meanwhile, Raj decides he wants to settle down and asks his father to find him an arranged marriage.

The Procreation Calculation

Series 12, Episode 3 Unrated CC HD CC SD

Howard and Bernadette’s life gets complicated when Stuart (series regular KEVIN SUSSMAN) starts bringing his new girlfriend home; Meanwhile, Penny and Leonard talk about starting a new family, as Raj explores an arranged marriage.

The Tam Turbulence

Series 12, Episode 4 Unrated CC HD CC SD

When Sheldon won't tell anyone why he's never mentioned Tam, his childhood best friend, Leonard takes matters into his own hands; Bernadette and Penny take Raj's fiancee out to dinner to get to know her.

The Planetarium Collision

Series 12, Episode 5 Unrated CC HD CC SD

When Amy doesn’t have time to work on super-asymmetry, Sheldon goes to great lengths to ensure she’s available to work with him even if it means accidentally sabotaging her career in the process.Meanwhile, Raj doesn’t want Howard to join him in hosting a show at the planetarium. BOB NEWHART returns as Arthur Jeffries.

The Imitation Perturbation

Series 12, Episode 6 Unrated CC HD CC SD

When Wolowitz dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny's Halloween party; Leonard is shocked when Penny doesn't remember their first kiss.

The Grant Allocation Derivation

Series 12, Episode 7 Unrated CC HD CC SD

The Consummation Deviation

Series 12, Episode 8 Unrated CC HD CC SD

Sheldon tries to bond with Amy's father, but when Wolowitz lures Mr. Fowler away with magic tricks, Sheldon has no choice but to bond with Mrs. Fowler; Koothrappali and Anu try to get physical for the first time.

The Citation Negation

Series 12, Episode 9 Unrated CC HD CC SD

Sheldon and Amy are devastated to learn from a Russian paper that Super-Asymmetry has already been discovered and disproven. Meanwhile, ultra-competitive Bernadette asks Stuart’s girlfriend, Denise (recurring guest star LAUREN LAPKUS), to teach her how to play the videogame Fortnite.

The VCR Illumination

Series 12, Episode 10 Unrated CC HD CC SD

A VHS tape from Sheldon's past inspires him not to give up; Bernadette turns into a pageant mom when she tries to help Wolowitz with his Magic Castle audition.

The Paintball Scattering

Series 12, Episode 11 Unrated CC HD CC SD

Penny and Leonard organize a paintball game that results in mayhem, when Sheldon is jealous of Amy, Raj catches Anu with her ex-boyfriend, and Stuart doesn’t want to move in with Denise.

The Propagation Proposition

Series 12, Episode 12 Unrated CC HD CC SD

Penny's ex-boyfriend Zack learns that he is infertile, so he asks Leonard for help; Koothrappali attempts to mend things with his ex-fiancee Anu.

The Confirmation Polarization

Series 12, Episode 13 Unrated CC HD CC SD

Sheldon and Amy are thrilled when their super asymmetry theory is proven by two physicists, until they try to kick Amy off the Nobel nomination; Bernadette has a big success at work.

The Meteorite Manifestation

Series 12, Episode 14 Unrated CC HD CC SD

Sheldon is thrilled to help Howard & Bernadette navigate bureaucratic paperwork… until he discovers they are breaking the law!

The Donation Oscillation

Series 12, Episode 15 Unrated CC HD CC SD

Penny tries to throw a wrench into Leonard's plan to be a sperm donor for her ex-boyfriend; Wolowitz, Bernadette, Anu and Koothrappali turn Koothrappali's canceled bachelor party into a couple's trip aboard the "vomit comet."

The D & D Vortex

Series 12, Episode 16 Unrated CC HD CC SD

When the gang finds out that Wil Wheaton hosts a celebrity Dungeons & Dragons game involving WILLIAM SHATNER, JOE MANGANIELLO, NBA legend KAREEM ABDUL-JABBAR and director KEVIN SMITH, deception and betrayal are the path to make it to the one open seat.

The Conference Valuation

Series 12, Episode 17 Unrated CC HD CC SD

When Penny and Bernadette got to San Diego for a pharmaceutical sales convention, Howard is left in charge of the kids. But when Sheldon finds a book on experimenting with children, the guys and Amy make a day of it.

The Laureate Accumulation

Series 12, Episode 18 Unrated CC HD CC SD

When competitors Pemberton and Campbell (guest stars SEAN ASTIN and KAL PENN) charm America on a publicity tour, Sheldon and Amy try to bring Nobel laureates KIP THORNE, GEORGE SMOOT and FRANCES ARNOLD to their side (this episode sets the record for most Nobel laureates appearing in a comedy). Meanwhile, Halley’s fear of the dark leads to both opportunity and conflict for Howard, Bernadette and Stuart.

The Inspiration Deprivation

Series 12, Episode 19 Unrated CC HD CC SD

The concept of what it would mean for women everywhere if Amy were to win a Nobel Prize causes Amy to have a meltdown. Meanwhile, Raj and Howard try to relive the good old days when Howard buys a scooter that resembles the one he had years ago.

The Decision Reverberation

Series 12, Episode 20 Unrated CC HD CC SD

While Raj is worried that people won’t take him seriously in his own field after publishing a paper suggesting he may have discovered alien life, Penny encourages Leonard to stand up for himself when he wants to be the principal investigator on a plasma physics study.

The Plagiarism Schism

Series 12, Episode 21 Unrated CC HD CC SD

When Barry Kripke finds proof that Dr. Pemberton plagiarized his thesis in college, Sheldon and Amy aren’t sure if they should turn him in or not. And Howard is happily surprised to learn that Bernadette wasn’t the only waitress at The Cheesecake Factory who had a crush on him back in the day.

The Maternal Conclusion

Series 12, Episode 22 Unrated CC HD CC SD

Leonard is pleasantly surprised when Beverly comes to visit and she's genuinely kind to him, until he finds out the real reason she's there; Denise and Stuart overstay their welcome at the Wolowitz house.

The Change Constant

Series 12, Episode 23 Unrated CC HD CC SD

Everything changes as Sheldon and Amy await big news in the first of a two-part series finale.

The Stockholm Syndrome

Series 12, Episode 24 Unrated CC HD CC SD

It’s an end and a beginning on the second of a two-part series finale. Howard and Bernadette leave their kids for the first time; Leonard and Penny try to keep a secret; Sheldon and Amy stick together; and Raj makes a new friend as the gang travels together into an uncharted future.

The Big Bang Theory Season 11 Recap

Series 12, Episode 100 Unrated HD SD

A collection of some of last season's hilarious and most memorable moments.