At common law, criminal conversation, often abbreviated as crim. con., is a tort arising from adultery. "Conversation" is an old euphemism for sexual intercourse that is obsolete except as part of this term.

It is similar to breach of promise, a tort involving a broken engagement against the betrothed, and alienation of affections, a tort action brought by a spouse against a third party, who interfered with the marriage relationship. These torts have been abolished in most jurisdictions. The tort of criminal conversation was abolished in England and Wales in 1857; in Northern Ireland in 1939; in Australia in 1975; and in the Republic of Ireland in 1981. Prior to its abolition, a husband could sue any man who had intercourse with his wife, regardless of whether she consented – unless the couple was already separated, in which case the husband could only sue if the separation was caused by the person he was suing.

Criminal conversation still exists in parts of the United States, but the application has changed. At least 29 states have abolished the tort by statute and another four have abolished it judicially. The tort of criminal conversation seeks damages for the act of sexual intercourse outside marriage, between the spouse and a third party. Each act of adultery can give rise to a separate claim for criminal conversation.

Malicious prosecution is a common law intentional tort. While like the tort of abuse of process, its elements include (1) intentionally (and maliciously) instituting and pursuing (or causing to be instituted or pursued) a legal action (civil or criminal) that is (2) brought without probable cause and (3) dismissed in favor of the victim of the malicious prosecution. In some jurisdictions, the term "malicious prosecution" denotes the wrongful initiation of criminal proceedings, while the term "malicious use of process" denotes the wrongful initiation of civil proceedings.

Criminal prosecuting attorneys and judges are protected from tort liability for malicious prosecution by doctrines of prosecutorial immunity and judicial immunity. Moreover, the mere filing of a complaint cannot constitute an abuse of process. The parties who have abused or misused the process have gone beyond merely filing a lawsuit. The taking of an appeal, even a frivolous one, is not enough to constitute an abuse of process. The mere filing or maintenance of a lawsuit, even for an improper purpose, is not a proper basis for an abuse of process action.

Declining to expand the tort of malicious prosecution, a unanimous California Supreme Court in the case of Sheldon Appel Co. v Albert & Oliker, (1989) observed: "While the filing of frivolous lawsuits is certainly improper and cannot in any way be condoned, in our view the better means of addressing the problem of unjustified litigation is through the adoption of measures facilitating the speedy resolution of the initial lawsuit and authorizing the imposition of sanctions for frivolous or delaying conduct within that first action itself, rather than through an expansion of the opportunities for initiating one or more additional rounds of malicious prosecution litigation after the first action has been concluded."