This document summarizes the rule of strict liability established in Rylands v. Fletcher (1868). The rule holds that a person may be liable for harm caused, even without negligence, in certain situations involving dangerous things or non-natural uses of land. Specifically, the rule applies if 1) a dangerous thing escapes, 2) onto another's land, 3) due to a non-natural use of the land by the defendant. The rule was established in Rylands v. Fletcher, where water stored in a reservoir on the defendant's land flooded the plaintiff's mines through undiscovered shafts. Though the defendant was not negligent, he was still held liable under the rule of strict liability.