The show was filmed in front of a live audience and was produced by Warner Bros. Television and Chuck Lorre Productions. The Big Bang Theory received mixed reviews from critics throughout its first season, but reception was more favorable in the second and third seasons. Later seasons saw a return to a lukewarm reception, with the show being criticized for a decline in comedic quality. Despite the mixed reviews, seven seasons of the show have ranked within the top ten of the final television season ratings, ultimately reaching the no. 1 spot in its eleventh season. The show was nominated for the Emmy Award for Outstanding Comedy Series from 2011 to 2014 and won the Emmy Award for Outstanding Lead Actor in a Comedy Series four times for Jim Parsons. It has so far won seven Emmy Awards from 46 nominations. Parsons also won the Golden Globe for Best Actor in a Television Comedy Series in 2011. The series has so far won 56 awards from 216 nominations. It has also spawned a prequel series in 2017 based on Parsons' character, Sheldon Cooper, named Young Sheldon, which also airs on CBS.
In the apartment building where Sheldon, Leonard and Penny (and later Amy) live, the elevator has been out of order throughout most of the series, forcing characters to have to use the stairs. Stairway conversations between characters occur in almost every episode, often serving as a transition between longer scenes. The Season 3 episode, "The Staircase Implementation" reveals that the elevator was broken when Leonard was experimenting with rocket fuel. In the penultimate episode of the series, the elevator is returned to an operational state, causing Sheldon some angst.
The show originally centered on five characters living in Pasadena, California: Leonard Hofstadter and Sheldon Cooper, both physicists at Caltech, who share an apartment; Penny, a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's similarly geeky and socially awkward friends and co-workers, aerospace engineer Howard Wolowitz and astrophysicist Raj Koothrappali. Over time, supporting characters were promoted to starring roles, including neuroscientist Amy Farrah Fowler, microbiologist Bernadette Rostenkowski, physicist Leslie Winkle and comic book store owner Stuart Bloom.
Sheldon needs half a billion dollars to prove his latest concept of string theory, which the University cannot afford to fund. Crowdfunding and selling some of his most valuable comic books to Stuart give him a small start. When Raj mentions gambling in Las Vegas, Sheldon goes there but is caught calculating odds by security before he can make any bets. Meanwhile, Amy takes Penny and Bernadette shopping for her wedding dress. She loves an old-fashioned one that the other girls admit that they find ugly, though Penny assures Amy she can make her own decisions about her wedding. Sheldon, however, comes home and sees Amy in the dress and loves how she looks.