Editing Patent (section)

===Effects===
A patent does not give a right to make or use or sell an invention.<ref name="Herman"/> Rather, a patent provides, from a legal standpoint, the [[Natural and legal rights|right]] to ''exclude others''<ref name="Herman"/> from making, using, selling, offering for sale, or importing the patented [[invention]] for the [[Term of patent|term of the patent]], which is usually 20 years from the filing date<ref name=PatentLength>Article 33 of the Agreement on Trade-Related Aspects of Intellectual Property Rights ([[TRIPS]]).</ref> subject to the payment of [[maintenance fee (patent)|maintenance fees]]. From an economic and practical standpoint however, a patent is better and perhaps more precisely regarded as conferring upon its proprietor "a right to ''try'' to exclude by asserting the patent in court", for many granted patents turn out to be invalid once their proprietors attempt to assert them in court.<ref name="lemley-2005">{{cite journal |author=Lemley, Mark A. |author2=Shapiro, Carl |year=2005 |title=Probabilistic Patents |journal=Journal of Economic Perspectives, Stanford Law and Economics Olin Working Paper No. 288 |volume=19 |page=75 |doi=10.2139/ssrn.567883 |s2cid=9296557}}</ref> A patent is a limited property right the government gives inventors in exchange for their agreement to share details of their inventions with the public. Like any other property right, it may be sold, licensed, [[mortgage law|mortgaged]], assigned or transferred, given away, or simply abandoned.

A patent, being an exclusionary right, does not necessarily give the patent owner the right to exploit the invention subject to the patent. For example, many inventions are improvements of prior inventions that may still be covered by someone else's patent.<ref name="Herman"/> If an inventor obtains a patent on improvements to an existing invention which is still under patent, they can only legally use the improved invention if the patent holder of the original invention gives permission, which they may refuse.

Some countries have "working provisions" that require the invention be exploited in the jurisdiction it covers. Consequences of not working an invention vary from one country to another, ranging from revocation of the patent rights to the awarding of a [[compulsory license]] awarded by the courts to a party wishing to exploit a patented invention. The patentee has the opportunity to challenge the revocation or license, but is usually required to provide evidence that the reasonable requirements of the public have been met by the working of invention.