Defamation per quod is a common legal theory that allows someone to sue someone else for libel. Defamation per quod requires that the defendant publish a statement that contains certain facts and circumstances that impose a defamatory meaning on otherwise innocent or neutral words. One of the most well-known cases of this type is  considered by some to be Prosser's 'classic case'. In that case, the defendant newspaper published a report that the plaintiff had given birth to twins, a blatant lie, because readers knew that she was only a month married to the defendant.

The plaintiff's case requires proof that the statement was false, it was published in an unprivileged forum, and that the defendant acted negligently or recklessly. Defamation per quod requires the plaintiff to prove the damages or special harm caused by the statement. It is important to remember that defamation per quod is very complicated and requires extrinsic evidence to succeed. In many cases, it will be possible to win a defamation per quod lawsuit.

Defamation per quod is any type of defamation. False statements made by insurance companies, for example, are defamation per quod. False statements do not impute criminal conduct or chastity. Defamation per quod requires that the victim show that the statements caused actual harm. Patricia Hall sued the insurance company for defamation after receiving an ominous email that described her as unfaithful and sexually promiscuous.

Defamation per quod cases require plaintiffs to prove actual damages. These cases are rarely won on the basis of purely "advertent" claims, since plaintiffs must prove that the statements they have published are false. This is because they must provide additional extrinsic evidence in order to win. Further, plaintiffs must show that the statements were made on a public forum. If the publication is not true, the plaintiff must provide expert explanation or extrinsic evidence.

Defamation per quod requires that the plaintiff explain why the statement is defamatory. Like defamation per se, defamation per quod typically requires proving actual damages. Damages may be very difficult to calculate, but the plaintiff can employ an economist to calculate this. If the damage is substantial, the plaintiff may be entitled to a monetary award. There are many types of defamation per quod cases.

Defamation per quod lawsuits are often filed in state courts, but they are not as common in Illinois. In Illinois, plaintiffs must prove that the statements were true and caused actual damage to the plaintiff. They may also sue for a claim for defamation per quod, which is an injury that is not necessarily foreseeable. However, damages are a factor in defamation per quod lawsuits, so proving the exact damages can be difficult.