This summary is not the rule. The rule text controls.
If you or someone acting on your behalf gets rid of, damages, changes, or hides evidence that matters to a case, the court can punish you for it. This applies whether the evidence is thrown away, destroyed, altered, or simply hidden from the other side.
The punishment comes from Rule 37, which gives judges several options. A judge might tell the jury they can assume the missing evidence would have hurt your case. The judge could also block you from using certain evidence or arguments, dismiss part or all of your case, or in serious situations, rule against you completely.
This rule exists to keep both sides honest during a lawsuit. Evidence needs to stay available so the court can look at the full truth. If someone destroys or hides evidence on purpose, or even carelessly loses something they should have kept, they risk serious consequences that can hurt their chances of winning the case.