Rule 11-407 Subsequent remedial measures.

If someone gets hurt and the person or company responsible later fixes the problem or makes changes to prevent it from happening again, that fix generally can't be used as evidence against them in court. For example, if a store puts up a new warning sign after someone slips and falls, the injured person can't point to that new sign and say "see, they admit they were careless before." The law doesn't want to punish people for making things safer after an accident, because that would discourage businesses and individuals from fixing dangerous conditions.

This rule blocks the evidence from being used to prove things like negligence, a product defect, or that a warning was needed in the first place. However, the evidence can still be used for other reasons. For example, if the defendant claims they didn't own or control the property where the injury happened, evidence of the fix could help prove they actually did control it. It can also be used to challenge a witness who says the fix wasn't possible, or to catch someone in a lie during testimony.

In short, this rule protects people from having their safety improvements used against them as an admission of fault, while still allowing that evidence to come in for other honest purposes.