Knocking on Walls
A simple yet effective technique. Press the action button against a wall to create a knocking sound. This will attract nearby guards, allowing you to either sneak past them while they investigate or ambush them from behind. This is particularly useful in areas with limited cover or predictable patrol routes. Experiment with the timing and distance to perfect this distraction method.

Using Cardboard Boxes
Cardboard Boxes are not just for hiding. You can use them to fast travel between certain areas (e.g., the Helipad and Tank Hangar) by being picked up by a truck while inside a box. They also provide excellent mobile cover, allowing you to move through open areas without being immediately detected. Just be careful not to get run over by a passing vehicle!
Footprints in Snow
In snowy areas, Snake leaves footprints. Guards will notice these and follow them, potentially leading to your discovery. To avoid this, crawl through snowy areas or use the environment (like rocks or structures) to break your trail. Alternatively, you can use footprints to lure guards into traps or away from your intended path.
Compare advanced stealth techniques inMetal Gear Solid 2: Sons of Liberty