Evidence law seeks to improve the accuracy of the factfinding process in jury trials. The system is human and therefore imperfect. Juries sometimes convict the innocent and sometimes acquit the guilty. The goal of evidence law is to minimize these mistakes, at least as much as humanly possible. Evidence law functions largely through exclusionary rules, which prevent juries from hearing certain information. Exclusionary rules generally reflect jury mistrust. They are based on assumptions that jurors are sometimes irrational and biased, and therefore cannot be trusted with complete information. These assumptions are not always credible, and very often they are not supported by empirical evidence. Some of the resulting exclusionary rules are rank fictions. Other rules are rough compromises that, while not optimal in each individual application, are nonetheless justified on the whole because they reflect a more or less sensible trade-off between competing values. It is not always easy to distinguish the rank fictions from the rough but sensible compromises.