A more thorough explanation:

A writ of conspiracy is a legal document used in the past to bring a case against someone who conspired to harm the plaintiff. This harm could be in the form of falsely accusing the plaintiff of a serious crime like treason or felony. In such cases, the plaintiff could use the writ of conspiracy to seek justice.

For example, if two people conspired to falsely accuse someone of stealing, the victim could use the writ of conspiracy to sue the conspirators for damages. The writ of conspiracy was a way to hold people accountable for their actions and prevent them from causing harm to others through deceitful means.

Under common law, the writ of conspiracy was only applicable in cases where the plaintiff was falsely accused of a serious crime. In all other cases of conspiracy, the plaintiff had to file an action on the case.