The tone of the play is satirical and ironic: it is funny, but there is almost always something more serious going on beneath what the characters are actually saying. Congreve establishes this tone from the beginning, both in the prologue and in Act 1, Scene 1, when Fainall asks Mirabell about why he is in a bad mood while they are playing cards:
Confess, Millamant and you quarrelled last night after I left you; my fair cousin has some humours that would tempt the patience of a Stoic. What, some coxcomb came in and was well received by her, while you were by?
It sounds at first like Fainall is extending sympathy and genuinely inviting Mirabell to talk about his frustrating courtship with Millamant. As the scene goes on and more of the characters' relationships are revealed, however, it becomes clear that Fainall is also pumping Mirabell for information. For instance, here he refers to Millamant as his "fair cousin." She is actually the cousin of his wife, Mrs. Arabella Fainall. As it turns out, Fainall and Mirabell both have a stake in the same fortune controlled by Lady Wishfort. Fainall is curious not because he wants to support Mirabell, but rather because he wants to know how close his rival is to getting the money he wants.
Fainall's double-speak (the way he hides his real question in genuine-seeming concern) contributes to the satirical tone. It is comical to see all the characters be downright hostile to one another but try to cloak it in manners and feigned sweetness. The ways they pretend to be friendly toward one another are often quite witty, and the characters laugh at people like Sir Wilfull for seeming to be less able to keep up with this charade. As the play progresses, Congreve develops the comedy into a critique of how wit and the game of manners can lead to very bad behavior. Some wit, such as Mirabell's witty scheme, turn out to be good. But in a society where performative manners can get people very far, wit paired with bad intentions (such as Fainall displays) turns out to be troublesome. Fainall turns out to be abusive toward his wife, and the play does not let him get away with using marriage as a cover for his abuse. He is unmasked in the final act and ends up with even less wealth than he thought he started with in this scene in the chocolate house.
Audience members must be constantly on the lookout for hidden messages beneath what the characters are saying to one another, and beneath the surface of the comedy. Because the play requires this kind of critical eye and ear from audience members who want to feel like wits instead of fools, it also sets audience members up to criticize their own hypocritical use of manners as a cover for bad behavior. Although Congreve himself never delivers any lines, the entire play resonates with the sense that he is laughing at everyone.
