Left 4 Dead

At the end where you do the farmhouse part, an easy way to win is fill up with ammo. Get the health kit and find the barn. Climb up the ladder. You can sometimes find a ammo supply. You can easily cover the window and the bottom of the barn, Be careful when you need to get a rescue.

In Campaign Live or Versus mode, if you hit the machine a number of times then jump on top of it in a certain direction, it will send you across the screen.

Note: This requires an unpatched version of the game. In "The Construction Site", there is a metal door and a raised fence by the barricade that you burn. Jump on the fence and follow it until it begins to go downward. At this point, jump on the metal siding "door". Note: Some practice may be required.

In Survival mode (obtained by downloading the Survival Pack from the Xbox Live Marketplace), play Dead Air: Crane. This trick requires at least two people, but is more fun with four. If playing with three or four people, have one person hold A and run off the building onto the truck below. If done correctly you will be incapacitated. Have the next person run off while holding A + X. If done correctly, the second person will float down and sustain only 40 to 60 points of damage, but will be able to revive the person that is incapacitated. If playing a three person game, leave the incapacitated person for the next player to use to get down after activating the crane or leave the third person on the roof to die with the bot. On a four person game, have two people run off holding A, one person run off holding A + X, and leave one person on the truck for the person activating the lift. when You try this with only two people, one person must be incapacitated, and the other person must start the lift and run off while holding A + X, otherwise you cannot get to the street. You then must use your pain pills or health pack. Note: Do not use both, but the pain pills are the recommended choice. One at a time, jump from the hood of the truck and get past the wooden pole. Three things can happen when you do this.

• If you land past the pole you will sustain no damage and are officially on the street.
• If you land next to or near the pole, you will be incapacitated but will not die. Have someone revive you.
• If you land behind the pole, you will be incapacitated but will die immediately afterward. If someone tries to revive you they will also become incapacitated and die. If this happened, you have landed behind the point known as the "death barrier". If at any time you decide to walk past the wooden pole you will automatically die.

If you are on the street between the first two building you walk to, walk forward from where you land to find an alley. In this alley you cannot be attacked by zombies, and if a Tank tries to enter the alley he dies. However if you let a Tank follow you and are hanging out on the sidewalk and he is close enough to punch you, he can get into the alley. Note: If you jump rather than run off the building during the first step you will die even if you land on the truck. If you are going to revive an incapacitated person that is on the truck, do not jump off. Doing so will incapacitate you. In order to get past the pole you must use either the pain pills or health pack unless you are already in green health. Being in the alley for a long time will get boring. If you want to shoot zombies, stand on the sidewalk and shoot any zombies that come your way. You cannot be attacked by the Smoker Tongue unless you decide to stand in the street, but you can still be attacked by any other zombie (Hunters, Common, Boomers, Tanks). If you plan on staying on the sidewalk, bring any weapon of your choice but for extra fun bring the hunting rifle so you can snipe zombies off the rooftop.

Note: This requires an unpatched version of the game. In "The Crane", jump on the fence after climbing on the vent cover. Go across the fence then jump to the other side of the horizontal fence. Turn left and go to the end. Jump up and to the right to air conditioning unit box on the corner of the next building. Once on the next building, go to the left corner. Jump to the top branch of the tree below you. You will lose a lot of health after landing. However you will be at the next safe room.

Note: This only works with pain pills (or if someone gives them to you). There is water located near the location you get rescued (last stage). Before summoning the horde, duck underneath the water until you are incapacitated. Make sure there are teammates close by to save you. Let them help you up or give you pills if you need them, then use the pills under the water. Stand up after using the pills and your health will go to up to 124. Note: This was done under the Easy difficulty setting.

Note: This trick must be done online. When you are at the crane that triggers a car alarm, do not turn it on. Instead, stand behind it and become idle. You should be teleported to an alley beyond the crane. Note: If you do this, you cannot get back. Make sure you are prepared for a possible Tank.

• Note: This has only been tested on Versus mode online. When you start the campaign, jump on the wall that is away from the alley. When looking towards the street, go to the right. When looking down, you will see a white "board". Jump for the board. If you do not jump, you will be revived from your teammates and can try again. If you jump and miss, you will die. When you land on the board, heal yourself. Then, jump down to the ground. On the other side of the street is a desk-like object in front of an alley. Jump over the desk. Only common infected can get over that desk. That is all that that you can do. Stay away from the Hummer. If you get about five feet or closer to it you will randomly get killed.
  

• This can only happen on Versus mode and you must be a Hunter. Start by getting on the rooftop that is basically the building in the center of the map. Face the other end of the street, not where the gas trucker is found, but the other one. Aim for the light post. Jump and land on top of it. Jump up to the ledge on the building in front of you. Then, jump to the fire escape stairs. Run up to the top of the stairs, then jump on the roof. Go all the way to the back and turn left. Start walking. You will pass over an alley, and a second one you must jump over. From there, make your way beyond the buildings. Refer to this . You will eventually fall down to a street. There is here nothing of importance, but you are outside of the map.