The institution of an inter partes review does not mean that a patent is doomed. While the definition of obviousness does not change, the way the Patent Trial and Appeal Board scrutinizes the claims does change during the course of an inter partes review. The decision to institute an inter partes review and the final written decision are two very different analyses, and each applies a qualitatively different standard. The difference between the definition of obviousness at the institution of an inter partes review and the final decision can be confusing. Therefore it is helpful to review case law to clear up that confusion.