Learning disabilities and learning disorders have many causes and manifest in various symptoms. School-based prevention aims to identify and influence unfavorable developmental processes at an early stage to optimally shape individual competency development. The book first provides basic information about target groups and the prevalence of learning difficulties, and then discusses models to explain differences in school performance and learning disorders. Following this, fundamental questions of school prevention are addressed. The central chapters discuss and present general and specific school measures to improve educational development conditions and preventive support to avoid difficulties in mathematics.