Preemption

Preemption or pre-emption may refer to:

Legal

• Federal preemption, displacement of U.S. state law by U.S. Federal law
• "Preemption" is also sometimes used in the United States to refer to the displacing effect state laws might have on ordinances enacted by municipalities, especially in the context of alcoholic beverage laws, gun laws, zoning laws banning hydrofracking, and in the area of FDA approved pharmaceuticals.
• Preemption (land), a type of land transfer in the United States, as in the Preemption Act of 1841
• Preemption Line, the line that divided the Indian lands of western New York State, that had been awarded to New York, from those that had been awarded to the Commonwealth of Massachusetts by the Treaty of Hartford of 1786
• Pre-emption rights, the right of existing shareholders in a company to buy shares offered for sale before they are offered to the public
• FDA Preemption, legal theory in the United States that exempts product manufacturers from tort claims regarding Food and Drug Administration approved products
• Pre-emption (Dominion Land Survey), a purchase right given to settlers under the 1872 Dominion Lands Act

Other

• Preempt, a type of bid and a bidding tactic in contract bridge
• Preemption (computing), the interruption of a computer process without its cooperation in order to perform another task
• "Preemption", a form of broadcasting Blackout (broadcasting)
• Traffic signal preemption
• Preemptive war