|Part of the common law series|
|Trespass to the person|
|Principles of negligence|
|Strict and absolute liability|
|Other topics in tort law|
|Other common law areas|
An ultrahazardous activity in the common law of torts is one that is so inherently dangerous that a person engaged in such an activity can be held strictly liable for injuries caused to another person, even if the person engaged in the activity took every reasonable precaution to prevent others from being injured. In the Restatement of the Law 2d, Torts 2d, the term has been abandoned in favor of the phrase "inherently dangerous activity."
Several categories of activities are commonly recognized as being inherently hazardous; those who engage in them are subject to strict liability. These include:
Someone who is injured by one of these inherently hazardous activities while trespassing on the property of the person engaged in the activity is barred from suing under a strict liability theory. Instead, they must prove that the property owner was negligent.
In the United Kingdom, this area of law is governed by the rule established in Rylands v Fletcher.
Factors determining an activity is ultrahazardous: