In a civil case, what must the plaintiff prove to succeed?

In a civil case, the burden of proof is placed on the plaintiff, and to succeed, they must establish their case by a preponderance of evidence. This standard means that the evidence presented by the plaintiff must show that it is more likely than not that their claims are true. Specifically, this is often understood as the plaintiff needing to demonstrate that there is a greater than 50% probability that their assertion is correct, which is a lower standard than that required in criminal cases.

This standard allows civil cases, which often involve disputes between individuals or entities over rights, responsibilities, or damages, to be resolved based on the greater weight of the evidence rather than absolute certainty. As a result, the plaintiff does not need to prove their case "beyond a reasonable doubt," which is a standard applied in criminal cases. Although there is a standard of "clear and convincing evidence" in certain civil matters—primarily where heightened proof is required—this is not the general threshold for most civil cases. Similarly, the term "substantial evidence" is more often used in administrative and regulatory settings rather than as a standalone standard in civil litigation.