Criminal and civil discovery serve different purposes. Obviously, there are significantly higher stakes present in criminal cases, and that key difference plays out in the rules of discovery.
The goal of civil discovery, similar to the rules governing sporting events, is to ensure a level playing field for all parties. No one side should possess a procedural or evidentiary advantage beyond that which is particular to the specific facts of a case. The rules of civil procedure promote reciprocity and equal access to evidence.
On the other hand, one of the main goals in criminal law is the protection of a defendant’s constitutional right to a fair trial. The prosecution’s corresponding right is consequently limited. This difference affects trial strategy, particularly from the perspective of the party that bears the burden of proof.