A sample document that counsel may use to prepare an accused infringer's invalidity contentions, which are required in most patent litigation by the local patent rules, standing orders, or case-specific orders. It discusses common invalidity contention requirements, including identification of each invalidity theory and factual support, identification of prior art, production of supporting documents and information, and, if required by the local rules, a response to the patent owner's infringement contentions. This Standard Document contains integrated drafting notes with important explanations and tips.