Inadvertent, careless conduct that causes injury to another. The required fault is found in the failure of the wrongdoer to liveup to the degree of skill or care required in the circumstances. Important area of tort liability for professionals (businessppl) Main problem - for the court to determine what standard of care was required of the defendant & whether there was a failure to meet that standard. Used by court in many areas of law to establish standards of socially. Represents the standard of care expected from a prudent person who is being careful. To understand that the standard determined using the reasonable person test is not what would be expected of an average person. Can only e used where there is an assumption of both the legal risk and the physical risk. To avoid liability for negligence - the standard of care is reasonableness as opposed to average or perfection.