Trials have changed over the years. Modern trials consist of three phases: tracking, obedience, and protection. A dog must pass all three phases in one trial to be awarded a title, must have passed the prior level before allowed to compete, and may only acquire one title within a event. Each phase is judged on a point scale with a minimum score required to obtain a title. At any time the judge may dismiss a dog for showing poor temperament, fear or aggression, or failing one of several tests within each phase.