Character evidence is a term used in the law of evidence in the United States to describe any testimony or document submitted for the purpose of proving that a person acted in a particular way on a particular occasion based on the character or disposition of that person. There are three ways that such evidence might be presented in a court of law: Law (a loanword from Old Norse lag), in politics and jurisprudence, is a set of rules or norms of conduct which mandate, proscribe or permit specified relationships among people and organizations, provide methods for ensuring the impartial treatment of such people, and provide punishments for those who do not follow... The law of evidence governs the use of testimony (eg. ...

1. Testimony as to prior bad acts by the individual
2. Witness's own opinion as to the character of the individual
3. Testimony as to the reputation of the individual.

Civil trials

Character evidence is generally inadmissable in civil suits, because it is considered to be unfair basis from which to attempt to prove that an individual behaved in a particular way on a particular occasion. However, there are specific instances in which this kind of evidence is admissable. In particular, when an individual claims to have good character (particularly when a witness claims to be honest or peaceful), the opposing side can rebut this claim by introducing character evidence against that individual. Civil law has at least three meanings. ... In law, rebuttal is a form of evidence that is presented to contradict or nullify other evidence that has been presented by an adverse party. ...

Character evidence may be admitted where the character of the party is an element of the claim - for example, in a defamation claim where party A is suing party B because party B said that party is dishonest, party B can introduce evidence that party A has a reputation as a dishonest person.

Criminal trials

In criminal trials, the defendant may always introduce opinion evidence or reputation evidence to prove that they did not commit the crime of which they are accused, although the defendant can not introduce evidence of specific good acts to show that he did not commit a bad act. However, if a criminal defendant does introduce such evidence, the prosecution may then counter this with evidence of the defendant's bad character. Criminal law (also known as penal law) is the body of law that punishes criminals for committing offences against the state. ... In Common law, a defendant is any person who is required to answer the complaint of a plaintiff in a civil suit or any person who has been named in a criminal information or criminal complaint and stands accused of violating a criminal statute. ... Criminal law (also known as penal law) is the body of law that regulates governmental sanctions (such as imprisonment and/or fines) as retaliation for crimes against the social order. ...

When someone other than the defendant testifies as to the defendant's good character, the prosecution may ask if the witness was aware of specific bad acts done by the defendant. This is permissible because the question is not asked to prove the defendant's character, but simply to impeach the credibility of the witness.

Another exception arises in criminal trials where the defendant introduces evidence of the character of the victim of the crime, in order to show that the defendant acted in self defense. For example, if the defendant is on trial for battery of the victim, the defendant can introduce evidence that the victim has a reputation for violence, or that a witness has the opinion that the victim is a violent person, in order to show that the defendant actually acted in self defense. The prosecution may counter this by introducing similar evidence of the victim's peaceful nature, or by introducing similar evidence of the defendant's violent nature.

Distinguished from habit evidence

Character evidence must be distinguished from habit evidence, which describes conduct that an individual engages in as a matter of course, without giving it any thought.