The gold standard of optimization: A look under the hood of RollerCoaster Tycoon

RollerCoaster Tycoon (1999), created almost entirely in Assembly by Chris Sawyer, is considered one of the best-optimized games ever made, capable of simulating thousands of agents on late-1990s hardware. The article explores how this was achieved, using the open-source re-implementation OpenRCT2 as a window into the original code's aggressive optimization techniques. Beyond the use of Assembly—likely the last major game developed this way—every aspect of the game was meticulously optimized, from data types to simulation logic.