The Chaos Boost is the special ability used by Shadow the Hedgehog in Mario & Sonic at the Olympic Winter Games and Mario & Sonic at the London 2012 Olympic Games. It is a Chaos Power Shadow uses to gain a burst of speed.
When using Chaos Boost, Shadow harnesses the power of the Chaos Emeralds. Shadow will then float in the air and a red energy will surround him before disappearing. In gameplay, this grants Shadow an instantaneous speed boost before he then falls downs again. However, it can only be used during certain events.
To use the Chaos Boost in gameplay, the player must press . Like all the special abilities in the game, the player cannot do it twice in the same event.