Ancient Greek drama was semi religious, rooted in masked ritual. The masks worn by actors in Greek plays were large, with conventionalized features and exaggerated expressions; the wide mouth of the mask contained a brass megaphone to help project the actor's voice to the large audiences. These masks fell into two general categories, tragic and comic, with many variations for both types. In Rome, masks were used in comedy and by pantomimists.
In the mystery and miracle plays of medieval Europe, masks were used to portray dragons, monsters, allegorical characters such as the seven deadly sins, and, inevitably, the devil. The actor portraying God frequently wore a gilt mask. During the Renaissance, half masks covering the eyes and nose were used in the commedia dell'arte; these masks are the apparent ancestor of the modern domino mask, which covers only the eyes. Masks were employed in Renaissance courtly entertainments such as the masque and the ballet de cour, and they survived in ballet until the late 18th century. In modern Western theater, masks are used mainly to represent animal characters, although occasionally a playwright or choreographer experiments with masked personages, as in The Great God Brown (1926) by the American dramatist Eugene O'Neill.
In Indonesia, masks are used in village ritual dance dramas and in dramas derived from shadow-puppet plays. The traditional pageants and religious-didactic plays of China required masks representing kings, princesses, and grotesque characters, and the mystery plays of Tibet feature masked players representing demons and other spirits. In Japan, the most famous use of masks is in the No plays; made of lacquered or gilded plaster by highly respected artisans, No masks are admired for their subtlety of expression.