Since proving negligence is a vital aspect of all personal injury cases, fault must be clearly defined. In some states, if you bear any responsibility at all for the accident, no matter how small, you are unable to collect damages. Arizona operates under pure comparative negligence. This means you can recover funds from an auto accident, even if you are 99 percent at fault (although it is unlikely you would be attempting to collect damages if you were 99 percent responsible for the accident).