Combustion chamber design, through its strong influence on the rate at which energy is released during combustion, plays a key role in determining engine performance. To aid in understanding the effects of chamber design, the link is established, first, between energy-release rate and critical performance parameters such as efficiency, emissions, power stability, tolerance to dilution, roughness and knock. Design approaches are then explored for controlling the energy-release rate. Supplementing these general approaches is an examination of the effects of specific design features on energy release and engine performance. Finally, a number of contemporary engines incorporating these design features are reviewed.