A more thorough explanation:

The impact rule is a legal requirement in torts that states that physical contact must have occurred to allow damages for negligent infliction of emotional distress. This means that a person cannot sue for emotional distress caused by someone else's negligence unless they have also suffered physical harm.

For example, if a person is in a car accident and suffers physical injuries, they can also sue for emotional distress caused by the accident. However, if a person witnesses a car accident but does not suffer any physical harm, they cannot sue for emotional distress caused by the accident.

The impact rule has been abandoned in most jurisdictions because it is seen as too restrictive. Courts now allow for recovery of emotional distress damages even if there is no physical impact, as long as the distress was a foreseeable result of the defendant's negligence.

For example, if a person witnesses a loved one being injured due to someone else's negligence, they can sue for emotional distress damages even if they did not suffer physical harm themselves. This is because it is foreseeable that witnessing such an event could cause emotional distress.