Stealth is an important part of the game. It can be used for Hunting animals, escaping from pursuers, preparing an ambush, sneaking in hostile areas, and silently taking out enemies. While crouching, movement is restricted a bit but you make less sound while moving and you can’t be seen easily. This can be further improved by getting the perks “Sneaky Sprint” and “Ghost” perks under the Assassin category.
Even while crouched, make sure you’re not within the enemy’s line of sight. Even when they’re at breath’s end, as long as you’re behind cover (even inside the bushes), they won’t be able to see you easily and you’ll have enough time to perform a takedown. Even when an enemy has line of sight, a detection meter will appear. Once it’s full, the enemy will be alerted and in turn will alert everyone in his/her vicinity. Once you see the detection meter appear, break line of sight immediately or hide behind cover.
A stealthy approach will always give you an advantage especially when liberating outposts or laying down an ambush against armed convoys and other cultist vehicles. This will prevent enemies from activating alarms and calling out reinforcements or actively tracking you down in your general direction. Sniping from the same spot, even from a good distance, will still allow enemies to hone in to your position. If you plan on sniping targets, make sure to change locations actively.
Enemies will also be alerted if ever they spot their comrade’s dead body. If possible, try to hide bodies that can be seen easily. If not, you can use the corpse to lure another unsuspecting enemy that will examine the body for a few seconds and give you another free kill without alerting the base. The number of enemies that will react to a discovered body will depend on their range from the one who discovered it.
Finally, weapons. High powered weapons like Sniper Rifles, even when suppressed, will still alert enemies though they won’t be able to detect you immediately. Silent weapons like bow and arrows, slingshots, and suppressed non-automatic pistols can take out enemies from a good range without alerting anyone. However, these weapons cannot instantly take out tougher targets like angels, armored cultists, or the pyromaniacs. As such, you have to employ other means to silently take them out like Melee takedowns or save them for last and use a remote or well-placed explosive blast to kill them.