2. Introduction. PartiesForumsClaim ConstructionInvalidityUnenforceabilityInfringement. WillfulnessDamagesInjunctionsPatent ReformSample case. 3. Number of Patents in Litigation. 4. Parties. PlaintiffsAll legal owners of a patent must be joined as plaintiffs.Exclusive licensees can have standing to sue.DefendantsDirect infringers are those who make, use, sell or import.Indirect infringers are those who contribute to or induce others to infringe..