# Non-obviousness

One of the three core requirements for a utility patent. An invention is non-obvious if someone with ordinary skill in the relevant field could not have easily combined existing knowledge to arrive at the invention. Non-obviousness (35 USC § 103) is the most frequently litigated and most difficult requirement to satisfy — the line between "obvious" and "not obvious" is contested in almost every patent case.

**Full entry:** https://patentbrief.org/glossary/non-obviousness

**All patent terms:** https://patentbrief.org/glossary

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_Source: PatentBrief — https://patentbrief.org. A plain-English glossary of US patent terms._