Web-based intelligent tutoring systems try to fill the gap between human teachers and printed textbooks as distance learning aids. Actually, intelligent tutoring systems research is concerned with the development of computer tools that show adaptive capabilities in the domain of tutoring, where the student’s progress is autonomously monitored and guided according to some tutoring strategy. This paper provides details on the analysis, design and implementation of such a system. STIA (Sistema Tutor en Internet de Ajedrez) is a fully implemented Web-based tool developed to provide adaptive guidance and help while learning chess basics. In STIA the task of the tutor is to guide the student efficiently through the course material, according to the tutoring strategy defined by the course authors. This is achieved in two ways. First, it imposes limits on the portion of course material the students can access. This prevents them from getting lost in a flood of information. Second, the tutor evaluates each student’s knowledge through a set of problems, and according to result recommends reviewing theory, solving more problems or advancing through the course.