In the ancient Greek theater, acting was stylized; indeed, the large outdoor theaters made subtlety of speech and gesture impossible. The actors, all men, wore comic and tragic masks and were costumed grotesquely, wearing padded clothes and, often, artificial phalluses. Nevertheless, there were advocates of naturalistic acting even at that time, and actors were held in high esteem. In the Roman period actors were slaves, and the level of performance was low, broad farce being the most popular dramatic form. The tragedies of Seneca were probably read in declamatory style, rather than acted on stage.

During the Christian period in Rome, acting almost disappeared, the tradition being upheld by traveling mimes, jugglers, and acrobats who entertained at fairs. In religious drama of the Middle Ages, an actor's every gesture and intonation was carefully designated for performance in church, and, as with the later pageants under the auspices of the trade guilds, the actors were amateurs.

Modern professional acting began in the 16th cent. with the Italian commedia dell'arte, whose actors improvised convincing and entertaining situations from general outlines. During the Restoration period in England, Thomas Betterton and his wife Mary were famous for their naturalness of delivery, as was Edward Kynaston. Their contemporaries, Charles Hart, Barton Booth, and James Quin, however, were well known for their lofty, heroic acting, a style that became dominant in the first third of the 18th cent. In the mid-18th cent. Charles Macklin and his pupil David Garrick introduced a more naturalistic style, and similar movements took place in France and Germany.

The old declamatory method did not really die out until the early 20th cent., and such great 18th- and 19th-century actors as Lekain, Sarah Siddons, Edmund Kean, and Junius Brutus Booth would probably seem overly histrionic to modern audiences. Part of the reason for the persistence of bombastic acting was the star system that existed until high standards of ensemble playing—common in popular repertory theaters since at least Shakespeare's time—were set by the Meiningen Players in 1874. Important late 19th-century actors, varying considerably in the naturalism of their acting styles, were Edwin Booth, Dame Ellen Terry, Henry Irving, Eleanora Duse, and Sarah Bernhardt.

Acting in the 20th cent. has been greatly influenced by the theories of the Russian director Constantin Stanislavsky. An advocate of ensemble playing, he believed that an actor must strive for absolute psychological identification with the character being portrayed and that this identification is at least as important as mastery of voice projection or body movement. Stanislavsky's theories were popularized in the United States by the Group Theatre and later by Lee Strasberg at the Actors' Studio, which produced a generation of extremely naturalistic actors, notably Marlon Brando. The emergence of motion pictures and television has offered unprecedented opportunities and challenges for actors, the sensitivity of camera and microphone making subtlety of voice, expression, and movement absolutely essential.

For further information, see drama, Western; Asian drama; scene design and stage lighting; directing.