So sneaking around a guard just doesn't seem possible, but you still can't kill him. Here are some techniques for disabling the guard:

• First, keep in mind all the techniques for remaining quiet. If a guard sees you, it's very difficult to disable him with any of these tactics. Keep in the dark and stay quiet.

• Watch the guard's patrol pattern carefully. Does he come to a stop for any period of time? Is he walking away from you? If he comes to a stop or walks away from you, sneak up behind him and grab him. Crouch and gently advance with the thumbstick. Don't make a sound. When you near the guard, repeatedly tap the interaction button, and Sam will automatically grab the guard once he's within range.

• Soda cans and glass bottles are scattered throughout the missions. Grab one--it's perfect for distraction. Equip the can or bottle and toss it where you want the guard to investigate (nearly always away from you). When the guard investigates, he comes to a stop to look in the area. Take the opportunity to sneak up behind him and grab him. You could also incapacitate the guard with a ring airfoil or sticky shocker.

• Hide in the shadows and fire a ring airfoil round or sticky shocker at the guard. A headshot with the ring airfoil round is an instant knockout. Hit him anywhere else and you must grab the guard before he recovers from the blow. A direct hit on any body part with the sticky shocker is a knockout. These gadgets knock out dogs as well.

• Launch a diversion camera where you want a guard to investigate (typically away from your current position). Activate its whistle sound until the guard approaches at close range. Release the gas to knock out the guard. It even works on guard dogs.

• Fire a gas grenade at a group of enemies (it's really a waste to use a gas grenade on a single guard), and the knockout gas should incapacitate the entire group.

• If the situation arises, it's possible to land on a guard and instantly knock him out. You might be hanging from a wire or on a ledge. Drop off onto the guard to knock him out cold. The guard even breaks your fall.

• Launch a sticky camera at a guard's forehead. A direct hit in the middle of the forehead knocks the guard out.

• You can knock out a guard without grabbing him with a few punches to the head. It takes a couple of hits, however, and is definitely not recommended in most instances. While you're punching the guard's head, he's likely firing his weapon into your gut. It's not a fair trade-off.

• No matter how you incapacitate a guard, always pick up his body and place it in darkness (where the visibility meter is at the far left). Failing to do so sets off alarms later in the level. This can be disastrous if there's an alarm limit in the mission (such as in the CIA Headquarters mission).

If you'd rather play with firearms than stealthy gadgets (and as long as Lambert has given the go-ahead to use lethal force), then combining stealth with combat is your best option. You won't be able to run around Rambo-style and survive for very long. Still seek out dark corners and destroy lights at every opportunity. A safe hiding spot will increase your combat ability. Always go for headshots. If the guard survives a first hit, he could run to an alarm, alert other guards, or even fire in your direction. Look for opportunities to use the SC-20K's sniper scope. It makes combat much easier and safer. And don't forget to hide the bodies! One alarm can ruin your day.