An economic device used to protect against the risk of realizing unforeseen and extraordinary financial loss is called:

Subrogation is a legal process that allows an insurance company to pursue a third party responsible for a loss after compensating the insured. While it is related to insurance, it does not serve as a protective device against financial loss itself; rather, it is a recovery mechanism after a loss has occurred.

Risk avoidance refers to strategies aimed at eliminating potential risks before they can result in losses. While it can be an effective approach in certain scenarios, it does not function as a financial device for managing risks that cannot be avoided. Thus, it does not provide protection against unforeseen financial losses.

Indemnification is a principle where one party agrees to compensate another for loss or damage incurred. While it is often a component of insurance contracts, it is not itself an economic device. Rather, it describes the process of making someone whole after a loss has occurred, which is contingent upon the existence of insurance.