The Rules of Engagement specify under what conditions a soldier in the US Army may use force. In general, this means that you must obey the laws of war - you are not to attack civilians, surrendering enemy soldiers, medics, and the critically wounded. Above all, you are not to attack other US Army soldiers under any conditions.
There are several ways to tell friendly troops from OPFOR:
At close range, other US Army soldiers will show a green nametag when you aim at them. OPFOR soldiers will show a red nametag.
At long range, friendly forces are identifiable by their helmets and rucksacks. The OPFOR will not have these items.
When firing, American machineguns will be identificable by their red-orange tracers. The OPFOR will be firing green tracers (note that this is the reverse of the nametag colors).
Finally, the weapons of the US Army sound different, when fired, than those of the OPFOR.
Each time that you violate these rules, you will be penalized by the addition of ROE points, which directly reduce the amount of Honor you will receive for the mission.
The number of points of ROE is directly related to the damage inflicted on friendly troops by the attack (+40 for any attack which eliminates another US Army soldier).
You will be kicked and sent to Leavenworth immediately if you attack any US Army soldiers within the first 20 seconds of the mission.
ROE violations within the first 45 seconds count for double the normal value.
ROE violations when your crosshair or aiming pip is green (showing a friendly target) will count for double the normal value at any time during the mission.
All ROE violation modifiers are cumulative, so shooting and eliminating another soldier at 42 seconds at close range (with a green crosshair) would give you (Damage+40)x4 ROE points.
If at any time you have a total of 400 or more points of ROE, you will automatically be sent to Leavenworth. This will also affect your Honor with an additional penalty.
The bottom line - �Friendly fire isn�t friendly.� Always check your targets and use planned avenues of approach combined with frequent and detailed communication to ensure that you do not accidentally fire on a teammate.
