Remember that fittest doesn't mean the strongest! It means the player that is most adaptable. You don't have to be a pro to survive and win on these servers.

At the start of the game you will end up with nothing. Pistols and a basic weapon against specials is like fighting a lion with a stick. At this stage of the game your primary goal is to find a melee. Melee weapons has the highest drop rate in these servers. You should gather with your team and push special zombies and shoot them in the head while they are stunned and you have a clear view. If someone picks up a melee before you then follow them. They will be the ones instantly killing the zombies and getting all the drops. You should also look for riot zombies as they carry a nightstick with them. Once you have a melee you should use the killing strategies under zombies until you obtain a strong primary weapon. It makes it easy if you use adrenaline with melee. You will have unlimited shove, run, and attack faster for 3 minutes.

Note

• Drop your pistols using the !drop command before killing specials for melee so that your secondary slot is empty. This will prevent you from accidently replacing your melee with pistols while spamming E.
  
• Load your basic primary weapon with explosives to instantly kill booomers or with fire ammo as it deals high damage over time to kill other zombies.

By now you should be half way from the safe room. At this stage you should have at least a melee. Some of your teammates should be dead so focus on bringing them back alive or protecting the remaining. Don't defib players unless it's safe. These are roles you will have to play depending on your status.

Play offense when you have a good primary and secondary weapon.

• Your goal here is to kill as much special zombies as possible.
  
• Don't face check specials each corner.
  
• Be careful about getting infront of players who are firing.
  
• Clear front waves of zombies.
  
• Don't go ahead on your own. Prepare yourself and move as a group.
  
• Be ready to retreat encase of tank or a charge.

Play defense when there are too many players charging at the front.

• Focus on protecting the front and back line from specials.
  
• Protect players that are healing, being helped up, or revived.
  
• Be alerted and ready to shove zombies off your team.
  
• Carry explosive ammo and knock off specials from your teammates.

Play support when there are a lot of supplies and there is no room to play offense or defense.

• Deploy upgrade ammo for your team.
  
• Defib and heal players.
  
• Kill zombies harming snipers
  
• Help the players who are being left behind.

By now you should be at the safe room and many should be alive if everyone worked as a team. If not then half of the team will have made it. When half of the team makes it and chooses to farm the chances of failing increases. Farming is the process of killing zombies for points or drops and usually lasts 3 minutes. If not much teamwork was involved then you can expect the zombies to finish the remaining players off. So it's highly recommended to play it safe and not farm. If people still chooses to farm then be ready to force open the door when things get messy. You should force open once there are 5 players alive. You can force open the door by just opening the saferoom after 1 minute instead of having to wait for it to automatically open after the remaining 2 minutes expire.

To effectively farm you will need good weapons, good cover, teamwork(fight in group/keep a distance), and to travel to the zombie spawn. From experience I learned that after you reach the safe room the zombies will start spawning at the back. If you are alone don't challange a super zombie. Retreat to the safe room and fight it with players nearby.

So you are the last person alive. This is where you have to use your head if you want to survive. You wont live unless you play really safe. Your goal here is to defib the best players closest to you from a 30 seconds walking distance. A good player by yourself makes a bigger difference than a random player when there's only two of you alive.

To play safe you must

• Camp whenever you hear a smoker, crouch, and shoot it once it appears. If you see it up ahead then shoot and take cover. Keep doing this until you kill it.
  
• Jockey, charger, hunter are killed behind a wall. This bugs the zombies as they wont jump you.
  
• Don't let boomer puke you. You will have to deal with a horde and specials with no vision
  
• Move forward when you know it's safe. Make sure you stop by another spot that is safe and kill zombies that appear while you are in that spot until it's safe. Slow and steady wins the race here. The idea here is to Move. Camp. Kill. Repeat(MCKR).
  
• If you are dealing with tank then your first goal is to find a molotov, burn the tank, then glitch it somewhere or run away.

Note

• You should also consider suiciding as well using the !cfs or !kill command. Consider this option only when continuing isn't worth it. For example, there are no weapons, melee, or health kit that the players that will be revived can take. If a fail box is open it isn't worth trying to win on your own unless it's the 4th round. Finally, if it's only the first attempt. You only get -10% for losing and it's much more efficient to restart if there are no drops/nothing valuable. Just take into account if it will be worth it.
  
• A lot of the notes about dealing with specials is covered in more details on the zombie section.

• AWP is a 1 shot kill weapon. Very effective against specials but weak against hordes of zombies. You can load it with explosives but wasting the explosives should be situational on normal zombies. This weapon should be your biggest priority. Using explosives is best with this weapon as it kills specials by just shooting their feet. Best to shoot their feet once and then aim for the head with the rest of the bullets when fighting super special zombies. The tumble grants you a couple seconds to aim the rest of the shots to the head.
  
• Scout is often a 2 shot kill weapon. Much like the awp but weaker in damage although it's a bit faster. This weapon is situational.
  
• Spas is good for close combat. Shove the specials then unleash this on specials. It's easy to aim for the head with this weapon so practice this! Despite the short range it's capable of handling smokers at a medium range.
  
• AK47 is a situational item. Most effective medium range. Can be used at closed and long range as well. I recommend going for this weapon when starting out. The accuracy isn't that good but just hold walk or crouch and shoot single bullets.
  
• M60 is similar to the ak but weaker in hard mods. The good news is that you can always load its ammo with upgrade ammo(fire/explosives). Once you collected 250 ammo and upgrade once more the gun ammo will upgrade to either fire or explosives depending on which one you chose. You will lose the ammo upgrade if you refill it again with ammo and will have to start over.
  
• SG552 is similar to M60 but its drop is more frequent. Consider getting this gun over any other unless it's any of the above. It's fairly accurate, comes with a scope, and does more damage than other gun not listed.
  
• Grenade launcher is very strong but difficult to use in hard servers. Shooting teammates is done very frequent and this gun often gets new players banned right away. Make sure to aim a bit higher and make the explosive land on the zombie legs. This weapon is strongest against tank and is capable of killing it within 15 shoots or so depending on the difficulty.

Note that you deal bonus damage when you aim for the head.

• Tonfa to deal with tank because it has the highest dps output.
  
• Katana/bat to deal with hordes or special zombies because of it's width at the cost of speed.
  
• Knife/machete to deal with special zombies. These are good situational items as they both have speed and can deal with hordes.
  
• Chainsaw for dealing with witches.
  
• Your first goal is to get a melee and kill as much specials as you can until it drops a buffed gun.

Note that knife, katana, and bat are good for beginners. Never use pistols for secondary. Always push then attack when using melee.

• Use bile on tank to let your teammates know where the tank is. Do not use it on the tank if the tank is already on fire. This will take off the fire effect and make it harder for your team to kill the tank. You get some points for using it on the tank but can only be done once.
  
• Pipe bomb is pretty useless on these servers. Can still kill hordes of zombie and knock back smoker.
  
• Molotov is the most handy as it can kill groups of specials, zombie hordes, and tank. Once the tank is on fire you can simply just run away from the tank until it dies. Be careful about throwing this near your teammates as it will kill them and get you banned for about an hour. When you burn a teammate by accident just quickly exit the game and rejoin. If you don't you will lose over 100 score point which takes hours to accumulate and banned if you reach the teamkill cap.

Note that water puts off the fire effect on the tank. So make sure you lure the tank away from water. Make sure you vile when the tank has about 10k(5%) hp left as this has the same effect as water.

• Defibrillator should be used imediately after someone dies. Prioritize on skills when few are alive.
  
• Medkits should be saved and used on black-white players.
  
• Don't heal or defib while zombies are attacking you or a special is approaching you.
  
• Don't heal players in the safe room. In these servers the players get fully or 50% healed at the beginning of the next map.
  
• Be ready to stop helping someone up as soon as you hear a special. They will catch you while you are reviving a player and if you aren't prepared to act then you will most likely die.
  
• Adrenaline on these servers are good. They increase your speed for 3 minutes and attack speed. Save these shots to kill tanks with melee, witches with shotgun, or when you need to rush to a place. One of the core items for offense players.
  
• Pills are situational. Save medkit when there are a lot of players alive. Save pills when there are very few players alive as it only takes 1 second to consume them.
  
• Gnome in most servers will heal you. You would be a fool not to bring him alogn with you.

• Always listen to the sounds of zombie hordes. Once you hear the hordes make sure you go to a safe place, pull your melee, and kill as much zombies as you can. Make sure to shove some zombies. The goal is to avoid taking as much damage as possible once you hear the horde. Watch your back as the zombies will spread around you.
  
• Go to sounds and turn on caption. This will notify you when a zombie is near. For example, boomer(zombie any) alert and hunter growl. This is useful as it serves as another method to detect zombies, especially if you are death(hard of hearing).
  
• Listen to the sound of specials. They indicate in what location they are and which special zombie it is.
  
• Familiarize yourself with the zombies spawning music. For example, piano music starts playing when a boomer spawns.
  
• Get ready to enter the safe room once you hear the saferoom door alarm. Chances are that you are going to die and no one is going to leave the saferoom to rescue you.

Note:
Get some sound add-ons if you find it more pleasant to listen to something other than zombies. I got quagmire for jockey and Alien VS Predator horde alarm which is more entertaining to me. If you don't like the current zombie sounds then its less likely you will pay attention to them.

• You will get kick for bad behaviours by moderators.
  
• You will get an automatic vote kick after inflicting a certain amount of damage to teammates. Normally it's 75 TK damage. Your teammates will decide to pardon your damage or not so let people know you are sorry and don't do it.
  
• You will get automatically kicked after dealing a higher amount of damage than what is acceptable. Normally over 200 TK damage. Kick's often last about 3 hours or so depending on the server/severity.

• Stop shooting whenever you deal damage to your teammate. A message will appear with the amount of team kill damage you dealt. For example, warning "Your name" has a total of [-20] team kill damage. Pay attention to this as it shows you when you are dealing damage to a teammate you can't see. The damage stacks and displays multiple warnings.
  
• Pipe bomb, molotov, bile, grenade launcher usually have a wide radius. Make sure your team is far away from you before using these.
  
• Spas, AWP, Grenade launcher, chainsaw, and molotov will often deal the most amount of damage to players. Therefore, avoid using these weapons unless you know how to use them.
  
• Use a melee weapon whenever you kill zombies close to your teammates. You usually lose 1 TK when you accidentally hit a teammate with a melee.

• Run away from it as much as you can. You are in big danger once you get puked so maintain a distance.
  
• Kill it from a distance whenever you can. Melee only when you feel safe.
  
• The boomer bumps you back when it attacks you. Make sure you are the first to push the boomer while it's puking then melee! The boomer will instantly knock you up the moment you get close if you do not stumble or kill the boomer while it's puking.
  
• If you choose to melee the boomer, wait for it to puke and kill it while it's puking. You can shove him while it's puking then use melee if you rather be extra cautious.
  
• Killing it near other zombies trigger the vile effect on those zombies. This causes the special zombies to turn against each other.
  
• Use explosives versus these zombies with any gun. It 1 shot kills them.
  
• Pushing boomers cancel their ability.

• Once you hear this be ready to shoot and stay close to a teammate. Smoker are extremely dangerous.
  
• Shove smokers off your teammates first then melee.
  
• Keep a distance between the smoker. They often instant grab you and kill you.
  
• If you cannot kill the smoker fast then consider shoving it and running to a teammate. Fighting them alone without any fire power or melee is lethal.
  
• Stay near teammates when smoker box is open and be ready shove.
  
• Fight the smokers on your own turf. Do not just wonder around and get caught. Listen, camp at a place, and be ready to shoot once it appears. Unless you have explosives don't feel confident in facing it straight forward.
  
• When you are sniping and it's a super special make sure you wait until the smoker uses it tongue before firing. Your goal is to cancel its tongue ability first then kill it. You don't want to have that 1 second reload each time you snipe with awp/scout or run out of bullets and have to reload the moment the smoker uses its ability.
  
• You can cut the smoker tongue with melee. Chainsaw usually gives you 100% chance of cutting it.
  
• Hide behind objects such as poles and trucks. You can easily break the tongue by hiding and counter attack.

• Another deadly special. Super will most often instant kill you before you can react.
  
• Be ready to dodge when you see a charger.
  
• Never fight a charger unless it has used its charge. You will regret it.
  
• Use fast melee when fighting chargers, especially super ones.
  
• Stay in high places and dodge a lot when a charger box is open. Listen for sounds!
  
• Remember you can kill chargers by hitting them in the head with a melee.

• Find rooms to fight the jockey. It jumps really high so go behind a wall and some place with a small ceiling so it's easier to shove them.
  
• Take cover behind a wall then push as the jockey approaches.
  
• Be ready to shove and move back. Move forward and shove once it has jumped, especially if they have missed you.
  
• Avoid using melee if you can. Shove then kill them with a deadly gun to avoid losing health. Use melee if it's super.

• Stay near teammates when jockey box is open and get ready to shove.

• Shove the hunter off your teammates or when it tries to jump you.
  
• Not as deadly as other zombies but you are as good as dead once it catches you alone.
  
• Use explosive ammo to knock back the hunter from a distance.
  
• Avoid using melee if you can. Shove then kill them with a deadly gun to avoid losing health. Try again with it's super or use melee from behind.
  
• They are easy to deal with by pushing. A good trick is to get behind a wall, wait for them to apporach(they wont launch at you), and push then melee.
  
• Stay near teammates when a hunter box is open and be ready to shove them off your teammates. Try finding some safe spots where they wont launch at you. Hiding behind walls is a good strategy but you will eventually die compare to finding a safe place to glitch them.
  
• You can use a teammate(incap) a bait to deal with hunters. Just make sure to protect them right away.
  
• Be careful when shoving them from the front. They will hurt you if you don't melee them within 2 seconds. I recommend using fast melees to deal with these such as tonfa.

• Avoid the spit at all cost. Dodge the spit then shoot.
  
• Learn to time when the acid will expired.
  
• Avoid using melee if you can. Shove then kill them with a deadly gun to avoid losing health. Use melee if it's super.
  
• If your health is below 40 then consider maintaining a distance as much as possible. Once it strikes you down with 1 hit you will most-likely die.
  
• They are easy to shoot in the head.
  
• Never kill them on top of a teammate.
  
• Get on top of a rail or something that the acid can't reach when a spitter-box is opened.
  
• Crawl away when a spitter box is open. The ability is usually activated.

• The tank will not hurt you when it attacks while you are on top of a teammate that is incapped. Instead, the incapped teammate will get hurt. Just make sure you melee the tank when doing this. You have to make sacrifices to win but not one's that will be in vain. Avoid doing this if the tank is burned.
  
• Each tank has special abilities so learn them so you can counter! EX: Gravity tank pulls you so keep a distance.
  
• Tanks are weakest to grenade launchers. Use fire upgrade for most damage and to trigger fire effect.
  
• Tanks can be glitched in certain spots. EX: ladders, generators, Etc...
  
• Tanks are slow so run away from them after burning it. You can hop over rails to slow down the tank and stall as much as possible while fire kills them.

• Using fire on the witch makes her slower
  
• Explosives stumbles the witch and can kill her if you use it with any shotgun.
  
• Best not to disturb the witch.
  
• Move back and hide from her sight if she's screaming.
  
• Run far away when a witch box is spawned and the witches are startled. They will aim at close players despite them not doing anything
  
• Throw a molotov on a group of witches and run. Let your teammates know what you will do so they don't get caught by the witch.
  
• Warn players when you will disturb the witch. Ask the to kill the witch while it's chasing you.
  
• Sneak behind the witch and aim to the head with a spas. Using fire ammo upgrade will cause her to react faster and kill you.

Without your teammates you are nothing. You will most likely die if there are only bots to help you or you are alone. One of the reasons you join 25 co-op is to be around many people. Therefore, you should create a positive enviroment to keep your teammates happy and keep them wanting to play more. Everyone needs each other in this game. You wont get far without them no matter how good you think you are.

You understand the importance of teamwork but how can you make your team effective? By communicating your ideas so your team knows where they need to go to win as a group. As the leader your role will be to guide your team and give them roles.

Examples on building better relationship and leadership

• If someone does good then praise them. A simple "good job" motives a perform on continue doing well.
  
• Let people know to use medkits on black-white players.
  
• Don't shoot when your teammates are very near you, especially if they are black-white. Either use melee or move away from your teammates before shooting. It's 25 players in a closed map so it's easy to hit someone.
  
• Make sure everyone uses defibs on anyone that is dead. There is power in number. Prioritize skills when there are only a few people alive.
  
• Share your weapons. Give a melee to a player if you already have a strong primary weapon.
  
• Share ideas you have in defeating bosses such as tank. For example, I'll glitch tank while the rest of you shoot it down. We burn the tank and run from it.
  
• Let them know when to play safe and camp or rush.
  
• Remind players of their roles. If someone has grenade launcher then get them to kill tanks and witches. If someone has AWP then get them to kill zombies at a distance.
  
• Let your team know when supplies or weapons are nearby.
  
• Alert your team when specials or tank is nearby.
  
• Warn players who split from the group. The team gets weaker when devided and everyone counts.
  
• Never talk down to people. It makes them lose your respect and play worse. If you are angry then take a break or yell at the monitor. Avoid attacking your teammate as it drops their performance and enjoyment.
  
• Stop conflict. If two people are fighting over weapons or getting shot then try and ressolve the matter. Let the angry person understand how friendly fire or looting weapons work on the server.
  
• Don't open boxes near your teammates or in safe room. You can end up opening a fire/barrel box and kill everyone.

• Prioritize smoker, hunter, jockey, charger, spitter, then boomer in order. Especially when you are facing multiple zombies.
  
• Shove zombies off teammates as soon as possible then melee.
  
• Warn people when zombies are nearby.
  
• Go on spectate and ask players to heal you when you're about to die.
  
• Heal black/white players(their glow color is often white).
  
• Share pills/adrenaline with below 20 hp players.
  
• Give back items when people lose it by accident. Picking up a gun by mistake or getting teamkilled for example. This isn't mandatory but it's good sportmanship.
  
• Defib good players whenever you can.
  
• Consider when to press the trigger if teammates are nearby.
  
• Stop reviving/helping a teammate and push special zombies that are attacking your teammates. It takes about 40 seconds for someone on the floor to die but only 4 seconds for a special to kill your teammate.
  
• Use explosives to stumble the zombies.
  
• Take cover behind walls/trees when fighting specials.
  
• Learn the tank and zombies abilities off the server websites.
  
• Learn what each box does.
  
• Download add-ons that can improve your experience such as item radar mod(optional/list for future), a good panel so your screen isn't filled with too many stuff(mine lets you see which gun you have selected to prevent friendly fire), and training maps to help you practice against specials. I like an add-on that let's you play on 3rd Person Shooter and switch between. Some people might do bad with FPS view but a lot better in 3 PS so your aim style matters.

• Shoot while you are very close to people. Will lead to friendly fire in most cases.
  
• Swear/complain about losing weapons after you die
  
• Complain about people taking your stuff. As soon as a zombie drops something it's free for all.
  
• Hogging everything for yourself(using a medkit and taking another or using all the pills)
  
• Taking weapons dropped accidentally(bad sportsmanship)
  
• Walk in front of people while they are shooting/get out of position
  
• Fight zombies alone
  
• Split from your team
  
• Rush ahead by yourself
  
• Open boxes near a teammate
  
• Help teammates up when a tank is on top of them
  
• Help teammates up when they are incapped and crawling away from the acid

Any of these servers will pop-up on your steam group servers in the L4D2 Menu once you join their groups. I can't make any recommendations. Best way is to try them yourself and stay in the one you enjoy the most. Some servers are associated with others so if you try joining all of them you can end up getting over 500 steam group servers. This can be very annoying so just leave some of the groups if this is the case for you.

List:
• http://steamproxy-script.pipiskins.com/groups/legionzcoop
  
• http://steamproxy-script.pipiskins.com/groups/americasectorcoop
  
• http://steamproxy-script.pipiskins.com/groups/Vip-ClubParadoxOfficial
  
• http://steamproxy-script.pipiskins.com/groups/core-ss
  
• http://steamproxy-script.pipiskins.com/groups/ParadoxCoop
  
• http://steamproxy-script.pipiskins.com/groups/l4d_az

Key binding is simply adding a set of commands to your keyboard. When the keys are pressed the game will perform whatever command you bind to the key. In order to bind a key you must open console(usually is ~ if you have it enable under options) and type bind "key" "!say my first key bind". This will display in game "my first key bind" whenever you press the key that you bind. You can separate each command with semicolon(;) and use wait if you want the command to wait a couple of seconds before performing the next action. 100 equals 1 second. You can use !, sm_, and / to perform a command. So !rank, sm_rank, and /rank all do the same thing.

List of useful keybinds where x is the key being pressed.

• bind x "say !frags" to display total zombies killed
  
• bind x "say !vip;wait 50;slot1" if you are vip and want to buy a weapon without going through so much hassle.
  
• bind x "sm_drop" to drop items
  
• bind x "say /nick;say /bill" to change characters from l4d1 or l4d2 survivors depending on the map.
  
• bind x "say /nick;wait 1000;say /ellis;wait 1000say /nick;wait 1000;say /ellis;wait 1000" between characters every x seconds..

Note that keybind can disconfigure your keys so make sure to add them on keys that you don't use. I binded keys such as [,],',\,/,. as I do not use them for anything.

There will be times when you join a game and you find a microphone spammer. These servers have up to 25 players so the chances of finding mic spammer here is higher. It's hard to vote players in these servers as most of the time the kick feature is disabled. Therefore, you should follow these steps to mute the annoying player microphone.

Steps
1) Type !afk or find cover when doing this as it takes 1 second to die.
2) Open up console with the key ~ in game.
3) Type Voice_Show_Mute on the console and it will show you a list of players.
4) Type voice_mute # id of player to mute them.

And taadaaa! No more mic spam. There is a visual guide that covers using and enabling console plus muting players if you find yourself stuck.

Obviously adjusting your computer to maximize on performance is important. You don't want to have low frame rates. Having too many add-ons, computer overheating, and high video settings will hinder your PC Performance. Therefore, lower your video settings in l4d2 and create a power plan suitable to your machine.

Add-Ons
If you aren't a modder then avoid installing add-ons that are size of 100 MB. Otherwise, consider the options below. There are tons of guides out there to teach you how to do this.

• Optimizing the add-ons if you really want them. This means opening up the VPK files and reducing textures quality with Photoshop or any painting tool.
  
• Extracting sound mods and replacing them with the original l4d2 sound files. This will overwrite the original sound files of the game so you can make a back up of those files.

Power Plan
Optimizing your power plan for specific games is important. You don't want to run your computer at maximum performance on a game that only needs 20% of your computer power. Windows usually gives you an option on laptops to use computer on low, high, or balance to get you started.

1) Go to battery settings and create a new power plan to make a custom one(if on windows of course).
2) Leave the recommended settings and click create(should be balance by default). Head over to change plan settings and go to the processor power management section.
3) Adjust the maximum processor state to use the amount of energy your PC requires to run L4D2 without dropping frames. Mine is at 60% which prevents my computer from using 100% of the PC power. This prevents my computer from over-heating and using a ridiculous amount of energy on a game that doesn't even use 80% of my PC power.

Note: You can just get game booster to make this a lot easier.

Special thanks to all of you for taking the time to read, vote, and share it. If it doesn't then let me know how I can make this better. Thanks to my friends for helping me write this awesome guide. Without them I probably would had been a hopeless case. Finally, thank you Deadpool.