A more thorough explanation:

The Hilton Doctrine is a rule in civil procedure that applies to disputes between parties involved in an oil-and-gas lease. According to this doctrine, if a defendant's lease is challenged, royalty owners who would lose their rights if the lease were terminated are considered indispensable parties to the proceeding.

For example, let's say that a company has leased a piece of land for oil and gas exploration. The lease agreement includes a provision that grants a percentage of the profits to the landowner as royalties. If another party challenges the validity of the lease, the Hilton Doctrine would require that the royalty owners be included in the legal proceedings because they have a direct interest in the outcome of the case.

The Hilton Doctrine was established in the case of Hilton v. Atlantic Refining Co., which was heard by the Fifth Circuit Court of Appeals in 1964. The court ruled that the royalty owners were indispensable parties to the case because their rights would be affected by the outcome of the dispute.