React to Contact
When your squad/platoon receives fire from the enemy the following drill should be executed:
Step 1 (Cover) Take up the nearest cover and return fire. Identify the enemy, determine if the squad/platoon can properly engage the enemy, and if the fireteam/squad in contact can suppress the enemy. If not, deploy additional fireteams/squads to gain suppressing fire. If all fireteams/squads are deployed, the squad/platoon commander moves into position to observe and suppress the enemy. No further orders will be made and the squad/platoon will be used as a base of fire for the platoon/company.
Step 2 (Maneuvering) Determine avenues of approach to the enemy and deploy a fireteam/squad into position to seize the enemy position. Make sure the base of fire element keeps the movement covered or obscured from the enemy.
Step 3 (Assault) Report to the platoon/company commander. Take command of the assaulting fireteam/squad and signal the base of fire element to shift fire away from the area about to be attacked. Seize the enemy position.
Step 4 (Reorganize) Redistribute ammunition and supplies. Fill any sensitive vacancies and move the base of fire element into position to cover the most likely avenue of approach.
Video of how the Rangers do it
Unclassified Video explaing how the Rangers do it.