What legal standard requires that one party's story must seem more true than not?

The legal standard that requires one party's story to seem more true than not is known as the preponderance of the evidence. This standard is commonly used in civil cases, where the burden of proof is on the party bringing the suit to convince the court that their version of events is more likely to be accurate than the opposing party's. Essentially, it means that the evidence presented must tip the scales in favor of one side, making it more probable than not that their claims are true.

In contrast, clear and convincing evidence is a higher standard than preponderance of the evidence, used in some civil cases, indicating that the evidence must be substantially more likely to be true than not. Reasonable doubt and beyond reasonable doubt are standards applied in criminal cases, reflecting the necessity for a much greater certainty before a defendant can be found guilty. Thus, the preponderance of the evidence is appropriately the correct choice for this question.