A more thorough explanation:

Definition: Mistaken belief about something other than the law. This can include misunderstandings about the meaning of a word or the identity of a person.

In criminal law, a mistake of fact can be used as a defense if it is reasonable. Even an unreasonable mistake of fact might work as a defense for crimes that require specific intent.

In contract law, a mistake of fact can be a reason to cancel or change a contract. If one party interprets a term one way, but knows that the other party interprets it differently, they should bring it up before the contract is signed. If they don't, the court may interpret the term against the party who knew about the possible mistake.

Examples:

• John buys a painting from a gallery, believing it to be an original work by a famous artist. Later, he finds out that it is a forgery. This is a mistake of fact, and John may be able to get his money back.
• Sarah is accused of stealing a car. She thought it was her friend's car and didn't realize it was stolen. This is a mistake of fact, and Sarah may be able to use it as a defense in court.
• Tom signs a contract to buy a car from a dealership. He thinks the contract says the car has a warranty, but it actually doesn't. This is a mistake of fact, and Tom may be able to cancel the contract or negotiate a new one.

These examples illustrate how a mistake of fact can affect different areas of law, such as property law, criminal law, and contract law. In each case, the person had a mistaken belief about something, which had legal consequences.