Move the Mouse to see around.

Tap once to change the camera from Snake's right side to left side. Hold the button to zoom/focus on Snake's viewpoint and to peek from cover, useful when looking for small things near Snake and marking enemy from short distance. Press this while using a scope (binocular or weapon scope) to quickly zoom in/out.

Move (run) Forward.

Move (run) Left.

Move (run) Right.

Move (run) Backward.

Set Snake from running movement to dash/sprint. You can hold Shift or just tap it once while running. If you're not sure wether Snake is currently in run or sprint move, just hold the Shift when he's not moving and look at his stance.

Hold Ctrl to set Snake from run to walk and sneak when in crouch stance, tap once while sprinting to quickly change from dash/sprint to run.

Tap once to change stance from standing to crouch and vice versa. Hold to change stance from standing or crouch to prone. While in prone, tap once or hold to change from prone to crouch and standing respectively. Press when hanging to drop down.

Perform a quick dive, useful for quickly hide from enemy when they noticed something suspicious (you) and avoiding enemy shots and grenades. Press W,A,S,D while pressing Space to quickly walk in crouch stance or run in standing stance. If you want to go prone, just press Space and release W,A,S,D when Snake dive.

Hold the button to use binocular, useful for reconniassance, marking and listening to the enemy from long distance. Scroll the middle-mouse to slowly zoom in/out.

Also known as Action Button. Context-sensitive, use this to interract with surrounding like climbing, hanging up, lock picking, get in car, etc. Press when hanging to pull yourself up.

Open iDroid menu. Press 1 or 3 to change tabs, W and A to choose menu, press Enter or Left-mouse button to select menu. In Map and Call Chopper menu, move the mouse while holding Shift to rotate map and change map angle, use V to zoom in/out.

Turn vehicles and spotlight light on/off.

Press while chocking to slit enemy throat with a knife and kill them.

Lethal guns as non-lethal

You can indirectly use rifle or handgun as non-lethal weapon. You just need to shoot enemy four times (normally, this will make them dying), then quickly approach them and use Left-mouse button to kick and render them unconscious. Please note that your firing distance will affect the damage inflicted, so how many shots you fired to make enemy dying won't be always the same. It would be safer if you aim for their legs or arms if you want to do this. Make sure you shoot the enemy from a safe/far distance when using shotgun and/or sniper. Note that if they regained their consciousness they'll continue dying.

This thing is really useful for distraction, throw it around nearby enemy to make a sound. If you don't have any weapon but this one and accidently spotted by enemy from close distance it's better to use Empty magazine to knock enemy out by aiming and throw it to their forehead, but make sure you have Reflex Mode on, since it's almost impossible to do this without Reflex Mode. And don't try this when spotted by far away enemy. It's actually not limited to Empty magazine, all throwable weapon like grenade could be used this way.

You could also plant a C4 on an enemy soldier (i don't want to spoil the fun so you should find out by yourself on how to use this as strategy).

Helpful for finding enemy (especially in dark place). You could also use this to see enemy through smoke when throwing a smoke grenade.