General Strategy
These strategies are designed for 4 man teams
NOTE - Some of these will seem common sense, but on more than one occasion, people have not done them. They are in no particular order.
1) Know thy team mates. If a person is covering an area and they go down, i means that there is an enemy coming that way. Send a person there to kill the enemy
2) Don't go it alone. There are 2 good reasons for this. the first is that if you come across an enemy by himself, he will be outnumbered, and you will be virtually garaunteed to survive the encounter. Second, if you encounter a group of enemies, you will need your partener's cover to fall back to a better position.
3) Leapfrog. This goes hand in hand with the not going alone part. If you and your team mate are manuvering down a hall with obstacles, or are coming around a corner, take it in chunks. The person in lead ducks behind an obstacle ahead, then the person in second runs past them (with the lead person covering them incase of surprise attack) and ducks behind the second obstacle. now the lead goes past the second, with the second covering them, and so on. if there are three or more people, the person in the very end is looking back to prevent surprise attacks. Around corners, the lead person looks around the corner (pops in and out) then if it is clear, he gives the go ahead, and they advance. if it is not clear, use the cover fire strat for corners.
4) Cover fire. This can be used in two ways. one as a diversion for the rest of the team to flank the enemy. two, as a way of buying time for a VIP (VIP means VIP in AS, Bomb carrier, or someone with a defuse kit) to get to safety. Here is a way of providing cover fire as a distraction to make the people distracting seem greater in number. Since this will usually be preformed at a choke point, you need at least two people. one pops up from around the corner, and fires four rounds at the enemy, not trying to kill (but hey! if you gett him great!). as soon as he returns from around the corner, the second person pops out and fires four rounds in the same manner. then they return behind cover, and the first person goes again. if you are in a corner of a hall, have the first person randomly fire a few shots in the general direction of the enemy. while they duck for cover the second person chucks a grenade bhind their cover. this does two things either they stay and get hit, or they leave their cover to be torn apart by the first person.
5) Choke points. Choke points are places in a map where the enemy has to go, or you have to pass through and there are no other ways. these are great places to set an ambush, so be wary when passing through them, and if you're defending, use them to your advantage.
6) Team work. While a single VERY good player may be able to let your team dominate, a well coordinated team will do twice as well. know who is covering what defense positions, and which attack paths they are taking.
7) Manners. many servers turn FF on, and you may accidentally injure or kill a teammate. if this happens, appologize. it lets them know it was a mistake, and your not just doing it to take their gun. otherwise you'll get TKed by them as revenge.
8) Communicate. If you spot an enemy, let your mates know where they are and or where they are heading. also, if you're on a sweep looking for the one remaining enemy. tell your mates where you are sweeping and what areas are clear. that way if you die, they know where the guy was hiding, and people don't sweep areas you've cleared. also, let peeps know when you are about to chuck a grenade that way they can get clear.
9) Stealth. this is one which is more or less optional, but many people stalk their enemies and go for a kill in the back a point blank range. turn the volume up so that you can hear foot steps, rolling grenades, and gunfights. This will tell you how close the enemy is without having to expose yourself Walk when you know an enemy is near. thye can't hear you, but you can hear their foot steps. this lets you hang by a corner that they are about to turn around, and you can open fire before they see you. Along with the sneaking around, if you see an enemy who is unaware of you at a considerable distance, don't take the sniper's shot. sneak up to them and go for the garaunteed kill.
10) Hide. If you are the last person on your team. do not be afraid to hide. wait until the enemy passes you by and then use stealth tactics to take them out from the rear. also, if you are sniping, choose a dark place where they can't really see you. gives you cover from people making quick checks.
11) Be Quick! if you are in a situation where speed is needed, be sure to to a quick 360 every once in a while while you are running to make sure no one is sneaking up on you.
12) Know they weapons. Use weapons that are appropiate for the firefight situations you find yourself in the most. if you find that you are always getting into pointblank range fights, use a shot gun as your main weapon for medium range fights, use semi-autos. the spread is just small enough so that if you aim at the body all the shots hit. in long range fights use rifles. the zoom in feature lets you stand a chance against snipers and lets you catch an unsuspecting camper with a devatating first hit. in extreme range fights, use the sniper rifles obviously. pistols are very accurate on the first shot. if you find yourself in a long range fight with a shot gun, take out the pistol and send a few shots (not holding down the fire button) to the sniper. if you hit him, he'll think twice before popping out of cover again.
13) be smart. if you are in a situation with a sniper and you are low on ammo, play the odds. there are very few snipers that can hit a randomly moving target. pop out of cover and duck back. the sniper will usually take a shot. do this to force them to run outta ammo. this make take a while, but use it as a last resort. if you know an enemy is heading towards you, see if there is a way to take a corridor to get behind him. that way, you have the drop on him AND he has to turn around before he can hit you. In the defusion maps, if you are a CT and the bomb is going to go off, don't try to defuse it. wait it out. it'll be better usually to let them get the win and you keep your expensive equipment than to let them win and you die.
14) Head shots! head shots will kill quicker than body hits. know where to aim with each weapon so that the recoil will force the bullets up into the head.
15) gang up. if there are two of you and one of the enemy, get the enemy from both sides. they have to choose who shoot at, and while they are shooting at one, the other will kill him.