Abstract: An inflatable jacket having a network of internal pressure air compartments which cooperatively communicate with each other through constricted airflow passageways, so that air displacement from one selected compartment is resisted by the pressure of the adjacent and other compartments; whereby said jacket, when used for example for karate, can cushion an external blow of significant force with pressure air of a nominal amount, e.g. 9 lbs. per square inch which can easily be supplied by a simple pump.