The style of George Bernard Shaw's play The Devil's Disciple is simple, clear, expository, unpoetic, humorous, and aphoristic.

The Devil's Disciple is one of Shaw's earliest play, but already shows several of the characteristic features of his style. The stage directions are very detailed and apparently intended to be read by the audience rather than the director and actors, since no actor could precisely express Shaw's intention on the stage. These directions are more eloquent and expansive than the dialogue. For instance, Shaw begins his description of Mrs. Dudgeon with these observations:

She is not a prepossessing woman. No woman looks her best after sitting up all night; and Mrs. Dudgeon’s face, even at its best, is grimly trenched by the channels into which the barren forms and observances of a dead Puritanism can pen a bitter temper and a fierce pride.

A Shaw play is always an argument, and the dialogue in The Devil's Disciple is simple and forceful, relaying that argument to the audience as clearly as possible. Shaw cares more for clarity and intellectual conflict than realism, and this is reflected, for instance, in the way that Dudgeon coolly defends his theological views, as though he were teaching a class.

Shaw is famous for his aphorisms, many of which are uttered by the charming and urbane General Burgoyne, who is one of a long line of Shavian "supermen," including Caesar, Professor Higgins, Andrew Undershaft, and, of course, Jack Tanner (in the play Man and Superman). Burgoyne's wit is dry and aphoristic, often undercutting the drama of the play. When Anderson cries out to thank God that he was in time to save Dudgeon, Burgoyne' coolly remarks:

Ample time, sir. Plenty of time. I should never dream of hanging any gentleman by an American clock.

Shaw is never given to lyricism, and the style of the play is always simple and prosaic, with wry, understated humor such as this.