Inventive step and non-obviousness

The inventive step and non-obviousness reflect a general patentability requirement present in most patent laws, according to which an invention should be sufficiently inventive—i.e., non-obvious—in order to be patented. In other words, "[the] nonobviousness principle asks whether the invention is an adequate distance beyond or above the state of the art".

The expression "inventive step" is used in European Patent Convention and in Patent Cooperation Treaty, while the expression "non-obviousness" is predominantly used in United States patent law. The expression "inventiveness" is sometimes used as well. Although the basic principle is roughly the same, the assessment of the inventive step and non-obviousness varies from one country to another. For instance, the practice of the European Patent Office (EPO) differs from the practice in the United Kingdom.