“Ghost” hackers rely on stealth and subterfuge to reach their goal and avoid confrontation.
A Sample Ghost Infiltration: Check the entire perimeter of a restricted area and learn where Marcus can quickly and quietly enter from. Manually scan for enemies (or use the Quadcopter or cameras to tag them). Then creep up and strangle every enemy, one at a time, in complete silence, until you’ve neutralized all threats. Then complete the objective. This takes the most skill, is the most satisfying, and is the recommended method for a true DedSec hacker to use.
Strangulation from behind is the key method to remain undetected. It is the quietest takedown and won’t cause other foes to leave their patrol paths, unless they see a body, in which case seek cover and step out to throttle the investigating foe. Unlike tasering, strangulation is permanent. If you don’t want physical contact with your foes, resort to stun gun tasering or use electroshock devices. Be aware that foes will wake up, and long infiltrations may be compromised by enemies starting a search for you after they wake up.
The only other variant is avoiding all combat entirely. For this, you need a direct path to each objective already figured out and knowledge of patrol paths. This occurs by practicing each mission over and over again.