Instructions
Sneak past enemies when you can. Press "X" to crouch to keep your profile low and your footsteps quiet. Hold down "X" to go prone and crawl silently to stay hidden. Stay motionless when prone to camouflage yourself against ground when you have the Octocamo equipped.
Approach an enemy and hold down "R1," then push the analogue stick in any direction to throw him to the ground and knock him out instantly.
Shoot enemies with tranquilizer weapons, such as the Mostin Nagant or the Mk. II pistol to neutralize them from a distance without the fatal after effect. A shot in the head, crotch or backside will send an enemy to sleep instantly. A shot anywhere else on the body will take slightly longer to take affect, depending on the difficulty set.
Kill non-human targets when the game forces it. There are several instances, such as the suicide gekko rush in Act 4 and the bike chase in Act 3, where you are harassed by unmanned targets. It is safe to destroy these with conventional weapons as their deaths to not count as kills on your record.
Use any weapon to attack the bosses in the beast phase of the battle. Switch to a tranquilizer gun or use unarmed combat attacks to defeat them when they shed their armor.
Defeat Liquid Ocelot in hand-to-hand combat on top of the Conning Tower to complete Act 5 and finish the game.