The space that develops between two engaged combatants. If the space is sufficiently large then it may be difficult or impossible to manipulate or strike an opponent. This may represent an opportunity to escape. But it may also represent a momentary pause after which you will need to reengage with an opponent. In Tensoku Ryu we consciously strive to control voids. We create them when beneficial, and prevent them from developing when that is to our current benefit.