The idea behind using simulators in training is to make the scenarios as real as possible so instructors can observe, grade, and correct trainees' reactions. If training scenarios can approximate the stress of the street, they are good predictors of how an officer will respond under pressure. The scenarios test not just officers' physical skills, for example marksmanship, but their decision-making skills and their judgment. Officers who respond well to the training learn as much about themselves and their limits as they learn about tactics and procedures. These training systems cost from $25,000 to $125,000, depending on the kind of simulator -- live fire or laser, fire-back or not, etc. Smaller departments are pooling resources to buy a trainer and then sharing time in the system. Use-of-force training and evaluation simulators will continue to become more sophisticated, easy to use, and worthwhile as a tool for law enforcement, contributing to the goal of better prepared and more effective officers.