This summary is not the rule. The rule text controls.
When a regular witness (someone who isn't an expert) shares an opinion in court, that opinion has to meet two requirements. First, it must be based on what the witness actually saw, heard, or experienced themselves. They can't guess or speculate about things they have no direct knowledge of.
Second, the opinion has to actually help the judge or jury understand the witness's testimony or figure out a fact that matters to the case. If the opinion doesn't add anything useful, it doesn't belong in court.
This rule keeps regular witnesses in their lane. They can tell the court what they observed and offer common sense conclusions based on that, like saying someone seemed drunk or a car was going fast. But they can't offer opinions that require special training or expertise, like diagnosing a medical condition or analyzing technical data. Those kinds of opinions are reserved for expert witnesses who have the right background and qualifications.
