Instructions
Select a unit or group of units that you want to use on patrol. Patrol units should have good mobility and you may wish to opt for inexpensive units (like zealots, marines or zerglings) as there is a fairly high chance that the unit will be destroyed during an attack.
Right-click on the part of the map that you want your units to start their patrol from. A patrol basically sets two waypoints, the first being where your units stand and the second is somewhere else on the map. If you don̵7;t want your units patrolling extremely long distances, send them to a destination close to the end of their patrol route first.
Click ̶0;Patrol̶1; from the unit action menu at the bottom right. Left-click somewhere else on the map to start the unit̵7;s patrol. If you are using medics, these units will stop and heal any damaged units they encounter, while SCVs will stop and repair and damaged mechanical units or buildings they encounter.