"Chekhov's Gun" is named after the Russian playwright Anton Chekhov, who once commented, "If you say in the first chapter that there is a rifle hanging on the wall, in the second or third chapter it absolutely must go off. If it's not going to be fired, it shouldn't be hanging there." The term is now used to describe any small element that is introduced into the story to be used later in the plotline.

W. S. Gilbert and Arthur Sullivan were a librettist and composer, respectively, who began teaming up in the 1870s to write comic operas. Throughout the next few decades, Gilbert and Sullivan wrote some of the most well known works of theater, including The Pirates of Penzance, H.M.S. Pinafore, and The Mikado. Gilbert and Sullivan's work highly influenced the development of musical theater in the twentieth century.

Henrik Ibsen wrote both of the plays Ghosts and A Doll's House. He was a 19th century Norwegian playwright. He is sometimes called the "father of realism."

The Faust story is an old one, told in traditional German folk tales, puppet plays, and songs, but Goethe retold the story of an intellectual who sells his soul to the devil to plough psychological depths. Goethe's story finds a man questing for a more fulfilling life, and being tempted by a demon to achieve this goal. Goethe's two-part play is the most widely performed and seen play in the German language.

Moliere helped popularize and develop theater during the seventeenth century by combining elaborate and genteel French comedy styles with the broader and more jovial Italian commedia dell'arte. Moliere's works such as The Misanthrope, Tartuffe, and The Miser all were essentially farces that mocked upper-class values, religious people, and social habits. These elements made Moliere equally controversial and influential in subsequent centuries.

The "Restoration" in "Restoration comedies" refers to the return of the monarchy to England under the Stuart King Charles II. Following the deeply Puritan Commonwealth of Oliver Cromwell, which banned all forms of theater and celebrations, theater companies and audiences found a taste for bawdy and over-the-top comedies that featured outlandish characters and bizarre situations.

Arthur Miller's Death of a Salesman won both the Pulitzer Prize for Drama and the Tony Award for Best Play in 1949. Its protagonist, Willy Loman, became a classic character of the American theater, thanks to Miller's story about the aged salesman and his fraught relationships with his family. Loman's struggles with work and disappointment in his sons provide the emotional depth for the character.

Arthur Miller wrote The Crucible in 1953, at the height of the second "Red Scare," when figures like Senator Joseph McCarthy were investigating Communism in America and targeting artists. Miller chose the Salem witch trials as a similar moment in American history when wild accusations generated by fear were prevalent. Miller himself was cited for "contempt of Congress" for refusing to name people he had seen at meetings of the Communist Party.

Jean-Paul Sartre's No Exit takes place entirely in one room, featuring three people who cannot leave. Reflecting some of Sartre's philosophy, the characters slowly realize that they are dead and in hell. The play closes with the famous final line "Hell is other people."

Luigi Pirandello's Six Characters in Search of an Author, which first premiered in 1922, was one of the first works in the genre known as "The Theater of the Absurd." Pirandello's metatheatrical work featured all of the characters in the play openly asking the director how the plot would unfold. Such groundbreaking work would prove influential to the next generation of playwrights, including Harold Pinter, Edward Albee, and Eugene Ionesco.