Scoring systems and risk prediction rules quantitate the severity of clinical conditions and stratify patients according to a specified outcome. In intensive care medicine, the complexity and number of clinical scoring systems is increasing as their utility in both health services research and clinical medicine broadens. We anticipate that with increasing healthcare costs and competition, the demand for risk adjusted outcomes and institutional benchmarking will increase. As academicians and clinicians, it is vital to be knowledgeable regarding the methodologies and applications of these scoring and risk prediction systems to ensure their quality and appropriate utilization.