Some of the prominent themes of "The Rivals" have to do with artifice, love, courtship and foolishness. In particular, Sheridan touches on the themes that artifice is ineffective, that true love and courtship often conflict, and that all characters act foolish in spite of their intelligence. In addition, many of the characters serve as symbols of social groups.
Artifice is seen all over the play. Initially, none of the characters present themselves as who they truly are. Jack, the main character, masquerades as Ensign when he is not truly poor in order to win the love of Lydia. Mrs. Malaprop peppers her vocabulary with impressive words to make herself appear more cultured. Yet all of these ploys are eventually revealed; Jack is eventually forced to confess his true identity, and Mrs. Malaprop's misuse of the very words that she employs reveals her uncultured nature.
Both arranged marriages and true love appear in this play. Captain Jack is in love with Lydia, and actively courts her. However when his father proposes an arranged marriage Jack rebels against this conventional route, even though his betrothed is, in fact, Lydia. Jack's refusal to accept his father's arranged marriage and the extreme measures that he has to go to in order to win Lydia's attention and stand out from other suitors show how inherently ridiculous the courtship system is in contrast with the simplicity of true love.
The theme of foolishness is seen in all of the characters throughout the play. Sheridan creates characters that are complicated and accomplished, but at the same time they often appear foolish. Lydia, for example, appears to be intelligent and well read. However, she is so into her sentimental and romantic novels that she almost passes up a gentleman who has all of the qualities that one would normally want just because he does not resemble the poor suitors of her novels.
Many of the characters, although complex in their own right, often represent entire social classes of the time. Mrs. Malaprop, for example, stands for an entire class of provincial people who try to imitate the rich.