Expert mode in l4d2/l4d is pretty challenging even for good players, because it takes all 4 of the players to coordinate and work together. There are some tips or rules, that you and your team should follow to increase your chances of survival.
Why expert so challenging
Maybe stupid question, with obvious answer, but here we go. Zombies take less dmg or have more hp, they do 20/10 dmg from front and back. Special Infected can drop your health to zero in a few seconds. Friendly fire can mean a down. WItches do instantkill. Tanks one hit = down and are harder to kill.
With that having in mind, one witch, one horde, a friendly fire accident can mean minus 100hp or minus a player, making it really hard to win the campaign.
Managing your Healing Items.
This might be the most important and basic rule all should follow. In this game as you progress, you get dmg and team’s total life can drop really fast. Most people would say, total life 4 x 100 + 4 medpacks. Thats actually wrong. In reality each player can go down 2 times before he dies. If he goes down a third time without healing, he dies. That means 100 + 2*30hp. Most naive players heal, after one down or even when their life drops below 40 or 30 hp. Medpacks should be saved at all costs. I understand after you go down your health drops per second, but you can always find pills and andrenaline shots to replenish temporally your health.
So rule number one heal only black and white (after 2 downs) and use pills and andrenalines instead.
Your objective for each chapter is to start the next one with at least 4 medkits and with decent health(not below 50). One tip to achieve that: when you reach the safehouse, do not close the door immediatly. Kill the survivors that have below 50hp, so they respawn next round with 50hp. Also kill them inside the saferoom, so that their drops to be available next round.
Managing your throwables
In l4d2 we have as we know 3 throwables. In expert they should be saved and used in tough situations.
Pipebomb is the only throwable that can counter a boomer. So throw it only when survivor(s) have been hit by a boomer.
Boomer pile, as we know is useless against a boomer’s attack. However, it can be used on tank and on the horde or during a panic event.
Molotov is the most important throwable and you should always have one. This one must be used on the tank. Lets face it tank is very hard to kill and during its attack you are very vulnerable. The best way to kill it is to throw molotov and retreat. Of course you can shoot the tank to kill it faster, but you should always focus more on the retreat part rather than the shooting part. Molotov is also useful for the witch. Witch should be avoided, unless she is in your way. I wouldnt risk to crown her or sneak past her (unless its open area and you can one by one, but there are situations that she can literally block your way in a narrow alley), since one hit means instant death. Molotov on the other hand can save your life because not only she loses hp/sec but it slows her significantly meaning you can outrun her. Witch always outruns the survivor, unless its on fire.
Things not to do: Using throwables at random situations or to clear a new area. You understand that you can create a horde that way. The duration of the throwable is not enough to clear all the zombies. So you are left with a horde you have to deal with.
Managing the Friendly Fire
FF can be a real issue in this diffuculty, meaning that one mistake can cost you a down. To compensate this I strongly advise you to avoid any shotgun weapon and of course the grenade launcher. Assault Rifles, smgs and snipers are more accurate, can be used to kill a zombie which is about to hit an oblivious survivor and also are useful for killing zombies and special infected from far.
I know its hard to say goodbye to that close range super clearing power, but trust me FF is a deal breaker for this difficulty.
Sometimes zombies are sneaky and can go behind or at the side of a fellow survivor, your instinct is to shoot like hell. Avoid it, if you can shove them away. Also, a survivor can be surrounded by zombies, try to clear those that are at the side and not front or back. If you shoot at his front or back you might hurt your teamate.
Managing your pace
Ok, lets talk about how fast you should progress the map.
If you go too fast, it means that you are rushing and you move through areas without proper cleaning them. Thats a big NO, because zombies can go behind or surround you and do some real damage(usually you go down, if you follow this pace).
If you go extremely slow, like clearing every area opening every door, that means that you waste more time in the map. More special infected are spawned and more hordes. Hordes and special infected are what makes this game challenging. Casual clearing areas is not hard.
So the solution is in the middle. When you go to a new area, clear everything you see, check those corners while you move. When there are no zombies, go faster, unless you are looking for valuable loot like molo and pills.
Managing panic events
Every chapter of a campaign usually has a panic event(excluding the first chapters), there are easy and harder panic events. Easy are the ones that you do not have to move/rush to a destination to stop that event. The best strategy is of course to camp somewhere and shoot anything that comes at you. Find narrow places that you can hole up until the event blows over. The rushing type is much much more harder, pipes and jars are advised to be used there.
Managing the walkthrough
In this game we have lets say the horde, special infected, tank and witch ( lets exclude the roaming zombies of the map), you can fight each one individually with ease even at expert. However, when combined it gets really challenging. When you move around, always check for special infected, if someones gets caught he goes down in 2-3 seconds. Also, when in close proximity do not try to kill the special, shove them first. Like i said in the beginning, infected are harder to kill, meaning that 2-3 seconds may pass before you kill them. So when a hunter gets your teamate and you are next to him first, then shoot him. At panic events or hordes tank spawning is your worst nightmare. To have chances you have to use molo on tank and then run back, focusing solely on not getting trapped by the horde or special infected.
There are situations that there is an upcoming panic event you need to rush and do not have health. You can be better prepared by killing the low hp survivors and hole up until they respawn. Never leave only one alive to wait. You must always leave two alive, but you need to know that the less you are alive the more vulnerable you are. So pick very wisely when to do that strategy. Sometimes you just need to heal, if you do not have pills. Panic events are the harsh part of the maps, but the good news are that you know the where and you can control the when.
Managing the finale
The finale, is undoubtedly the hardest part of the campaign. If you have followed the rules about the medkits and did well to the previous rounds, you should spawn at the final map with good health and at least 4 medkits. That means that during the actual finale, you are carrying 4 medkits and have 4 dropped medkits. You should be close to each other but not too close, there are many strategic spots at each campaign, find them and coordinate your team. Hopefully when the tanks spawn there is no horde. When you are facing the second tank be near the departure area. Also save every pipe bomb you can for that very moment. Zombie horde spawns as you wait for the boat,plane (or whatever you are escaping with), accompanied with tanks. Throw those pipes, do not get trapped or down by the horde and hopefully you escape before the tanks reach you.
Last tips( deeper tricks and details)
Rules are meant to be broken, when the situation requires it. You are in the end of the round and there is a panic event that might cost you victory, heal, sacrifice your medkits to increase your chances.
Also, you are like 10-15% of the map and you have done terribly. For instance at least 2 downs, (no tank yet). You can always restart the map, by tking everyone and dying and hopefully you will perform better and maybe the map layout will be easier. ( There are many times that witch spawns at very bad places and at very bad moments and cost us one survivor. In that case you either wait for respawn, or restart the map by becoming a serial killer).
Some deeper tips by rae
1. Bile works even when the Boomer got someone, throw it to another patch of upcoming infected and players won’t be focused on.(Better pipe, if you have)
2. Fire only slow the Witch in Night maps, her speed doesn’t change during the day. It takes 15 secs to burn her using fire. In Day maps, she will be wandering around, makes her easier to crown, even with chrome shotgun. Still, would not recommend crowning when:
a) You don’t know how to deal with her.
b) There are zombies nearby.
3. Shotguns are very viable. However, players with shotguns have go first, preventing misfire. If someone is taking a shotgun behind, it is better to aim at the feet, that way infected can be taken out in one shot, while lowering misfire chance to other players.
4. If there is a melee or Magnum, replace your starting pistol. While pistol dmg is higher than the M16, slower rate of fire, reload speed and low piercing power will severely limit Horde cleaning power. Be cautious with pistol choice.
5. Turn on closed caption is a good way to know what is around you. Sound cues texts will be displayed on the screen, letting you know what is coming.
6. You can clear zombies surrounding you with a 360 degree melee swing. Wider melee arc weapons such as katana, fire axe, etc.. will help more.
7. Jumping prevents stuns from Chargers, Hunters and Boomers.
8. Group of 2 is always required when the team scatters for objectives and item hunting.
9. Do not shoot and kill others without their consents. The AI Director will assist if the team is doing badly, by spawning more meds such as pills and shots.
10. Boomer bile on tanks is the worst idea of all time. Tank encounters are boss fights and the AI will usually disable other zombies spawns, including specials(Tank spawn during a panic event is very common, so having only to deal with the tank is unlikely).
11. Bile on Dark Carnival is very crucial. When you connected midgame and have the bile, do not waste it anywhere other than Map 4, which have a very long, narrow walk way ending.
12. AI Director has 30 zombies spawning limit. When you are running to the objective when someone throws a bile, do not shoot them as that will give the AI more zombies to spawn ahead of you.
13. Bile have 15 seconds duration, Pipe have around 6-7 secs. Time your nade well with the team to utilize as well as maximize zombie attracting power.