DEFCON 3, or condition level three has also been called "Round House" or "Yellow Alert" and is an increase in alertness and military readiness. With DEFCON 3 the air force is in a higher state or level of readiness so that they can deploy and mobilize within 15 minutes time. The alert color for DEFCON 3 is yellow, or 'yellow alert' level. The meaning behind Defcon 3 is similar to that of a yellow "caution" sign. We are prepared, cautious and in a state of military readiness. Round house is a state of preparedness and a high level of caution.

The alert status may be raised to Defcon 3 after a precision strike is carried out by an an enemy, or after a precision strike is carried out by the United States military or any event that warrants a cautious state of military readiness alert level by U.S forces.