There are four difficulty levels including recruit, regular, hardened and veteran with the major differences between each difficulty level being less efficient in combat during recruit difficulty, although still having a fair capability all the way through to a shoot on sight policy with unbelievable accuracy, flanking and sneaking up behind your character, throwing a grenade in front of you to force you into concentrating on
immediate evasive action instead of the imminent gunfire and even reacting to noise and nearby gunfire to quickly engage in further combat.