An expert system is a mechanism that acquires expertise from experts and delivers it to others. It has two main components: a knowledge base that contains rules and information, and an inference engine that applies reasoning to the knowledge base. Expert systems can be used to build tools like legal intake and triage systems. The Virginia Legal Aid Society developed an online expert system to improve the efficiency of its intake process by automatically screening applicants and referring ineligible cases to other resources in order to reduce unnecessary interviews. The system evaluated over 400 applicants in its first two months and avoided around 40 unnecessary interviews per week by identifying ineligible cases.