An impact rule is a legal rule which states that people who wish to claim damages for emotional distress must demonstrate that they also experienced physical harm. This applies to situations in which people sue for damages caused by negligent behavior. Intentional torts, such as defamation, which are designed to cause emotional distress are exempt from the impact rule, because proving that the defendant committed the act in question demonstrates that emotional distress occurred.
The reason behind impact rules is that it can be difficult to prove that someone has sustained emotional distress. People react very differently to different situations, and there is no clear measure for determining whether or not distress occurred and how severe it was. Having an impact rule is designed to prevent situations in which people file nuisance suits in an attempt to receive an award of damages.
A common example used to illustrate the way in which an impact rule can work is a car accident. If a parent and child are involved in an accident, and the child is injured but the parent is not, the other driver can be used for damages relating to the physical harm experienced by the child, but not the emotional harm experienced by the parent. Conversely, if the parent is hurt in the accident, he or she can file suit for physical and emotional damages.
Not all regions have an impact rule, and the interpretation of such rules is variable. Some judges are very strict about reviewing cases to determine whether or not they pass this test while others provide more leniency. People opposed to impact rules argue that it is possible to experience emotional distress without physical harm as a result of the negligence of someone else. For example, someone who witnesses a disturbing car accident may have nightmares or experience anxiety around cars without actually having been injured in the accident.
Rules of this nature are designed to prevent nuisance suits in civil law. While it is generally agreed that people who experience injuries as a result of the actions of others should be able to sue for damages, it is also agreed that some limitations are important. Without limits, there is a potential that someone could experience injury as a result of a recurring suit or series of nuisance suits. Balancing these limits to ensure that legitimate rights are not infringed by limits on civil suits is very important.