Acute pancreatitis has a mortality rate of 5-10%. Early deaths are mainly due to multiorgan failure and late deaths are due to septic complications from pancreatic necrosis. The recently described 2012 Revised Atlanta Classification and the Determinant Classification both provide a more accurate description of edematous and necrotizing pancreatitis and local complications. The 2012 Revised Atlanta Classification uses the modified Marshall scoring system for assessing organ dysfunction. The Determinant Classification uses the sepsis-related organ failure assessment scoring system for organ dysfunction and, unlike the 2012 Revised Atlanta Classification, includes infected necrosis as a criterion of severity. These scoring systems are used to assess systemic complications requiring intensive therapy unit support and intra-abdominal complications requiring minimally invasive interventions. Numerous prognostic systems and markers have been evaluated but only the Glasgow system and serum CRP levels provide pragmatic prognostic accuracy early on. Novel concepts using genetic, transcriptomic and proteomic profiling and also functional imaging for the identification of specific disease patterns are now required.