The Rockall Score was developed from a large UK national audit of 4,185 cases of acute upper GI bleeding in 1996, making it one of the most rigorously derived scoring systems in gastroenterology. The full post-endoscopy Rockall score incorporates endoscopic findings (diagnosis and stigmata of recent haemorrhage) in addition to clinical parameters, allowing mortality and rebleeding prediction after diagnosis has been established. A pre-endoscopy Rockall score (without endoscopic components) is less accurate but useful for initial risk stratification.