Battlefield 3 Multiplayer tips of various levels from basic to more advanced.

Set traps – When you have C4, or even better if you have Claymore mines.
Place your trap in a place that has only 1 or 2 ways to get to you, and try to cover the entry. Then get irritating – shoot a bunch of enemies up (even if you miss) or even just fire around a lot until you draw attention. When someone comes, set off your C4 (you have to be able to monitor someone’s approach) or if you used a Claymore, its set-it-and-forget-it. Just wait to hear the BOOM.

Set a different trap (the “Lure”) – Get REAL annoying by setting up a mortar and shelling the enemy. If they know what they are doing, they’ll come after you. If your team knows what they are doing, they will cover entryways to your position and shoot the “fish in the barrel” as they approach. Get ready though, you will get killed because after enough time they will probably get through. You could also use the MAV, a loud weapon, or anything that would grate on your enemies’ nerves to set a trap.

You can also find a place where some of your teammates have holed up and maybe even camped, and lure enemy soldiers into their sights.

Be ready at all times – When you are running around, when you are sniping (in the scope), when you are sitting still in that dark building where you can’t be seen, wherever you are you should be ready to start shooting at a second’s notices. First and foremost that means always reloading after you have fired your weapon, especially if you get close to empty. If your assault rifle is down to 5 bullets, you definitely need to be looking at where you can safely reload. If you have an M249 you might reload when you are in a “safe place” when you get down to 20-50 rounds (personal choice, of course).

So now you are in the habit (hopefully) of staying reloaded, now you need to be ready when an enemy soldier surprises you by appearing “out of nowhere” right in front of you. Right away you have to be aiming and firing (or firing then aiming, depending upon the situation). That means being ready to fire immediately when you run into someone face-to-face at short distance or when someone runs right in front of where you happen to be sitting/standing/camping.

Don’t get distracted by the MAV – If there is an MAV flying around you like a mosquito, maybe you can shoot it down. The dangers the MAV poses are a) it shows you on the enemy’s mini maps, and b) it can be used to kill you by running into you. The recon solider may just be trying to show his teammates where you are, or maybe hopes you will try to shoot his MAV down so he can get you to stand still long enough to kill you. The MAV, about as big as your torso in the game, will kill you by running into you. It may be better to ignore it or to run away from it trying to lose it. Or, if he’s following you close and you get into as tight space and the MAV follows you can toss a grenade, toss & detonate C4 on a nearby wall/floor (just don’t kill yourself, too) or even shoot it up with your rifle/SMG/PDW/MLG/shotgun. For even better results try shooting the MAV with a IGLA/Stinger missile or the Javelin AT rocket (not RPG or SMAW).

MAV As a Trap: Realize that the MAV, like the mortar and other loud or obnoxious weapons can be a trap.  The guy with the MAV doesn’t have to do well to keep your team distracted enough for his team to win. All he needs to do is either get you looking up or running around looking for him while he’s in a “safe” guarded location.

Get Used to Terrible Spawns – I’m sure EA/Dice are working on this, but sometimes you spawn right in front of an enemy who is facing you and get killed. You may even spawn with the enemy at your back!

Just tonight I spawned in front of a speeding jeep. Before I knew I’d spawned I saw the dog tags of the driver in my killcam.

Get Used to Death Glitches – I’m sure this is also being worked on too, but some places on some maps cost you your life. Like not being able to run over a curb, tire, or unseen “bump” without jumping. During the time it takes to stop, think, then press A you are often dead. Other spots trap you. On Seine Crossing there are many places where little pieces of debris you would run across in real life require a JUMP to pass. In the game this amounts to death as the “shock” of being stuck results in the familiar stop, think, press A. A building across the street from the Gas Station on Caspian Border (left side of gas station) has a tree at the corner of the building. Jumping around the corner of this building running toward the flank of gas station the other day I got stuck in the tree for fully 2 minutes trying to get out. Luckily no one stumbled across me before I got free.

Use Your Parachute – Yes, you have a parachute and it can be used to bail out of a jet or helicopter, but also when jumping off of high buildings. Surprisingly, the parachute seems to even be able to reduce the damage you take when you jump off of the second or third story of a building, although you have to press the open parachute button repeatedly and quickly to get it to open in time to slow your (very short) fall.