A law requiring that certain types of lawsuits be initiated within a specific length of time. For example, if a patient wishes to sue for malpractice, state law may require that the suit be started within two years after the date of the alleged act of malpractice (the length of time varies from state to state). In some states, the time period begins when the patient discovers (or should have discovered) the injury, rather than on the date of the alleged act of malpractice; this is called the “discovery rule.”