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For my guide on First Aid Kits:Proper Kit Usage

For my guide on Tanks and Witcheshttps://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=129879869

This marks the second L4D2 guide that I am writing. This guide is written to target Advanced/Expert players of Campaign/Realism modes, though it applies to all difficulties. Versus is much more dynamic, the rules change, and team strategies vary, but most of the guide will still apply as 'general rules' to Versus mode.

Some things to think about:

1. In Versus, Bile Bombs tend to be the worst choice. This is because generally speaking, players controlling boomers will land on at least one person. Also many players are accustomed to playing through bile covered screens, so both effects of Bile Bombs are diminished. Pipe Bombs are the most useful as you'll likely want to have outs in situations where 1 or more party members are boomed or incapacitated. Also, well thrown Pipe Bombs will force SI to disengage from you. Lastly, they can also be used to gain distance points relatively easily.

2. In Campaign, Bile and Pipe Bombs enable you to run long distances of the map with ease, while Molotovs tend to slow you down because you have to wait for the fire to go out.

3. In Realism, Molotovs really shine because they offer you ways of dealing with those pesky Witches and Tanks, and they also kill common immediately. In a mode where you're constantly chasing headshots, fire will come in handy and save you ammo.

4. Ideally, your party has one of each type of throwable on them at all times in preparation for when one is needed: Molo for Tank, Pipe for Incap+Boomer, Bile for Horde. Finding an extra grenade is not always a reason to throw one you currently own. If your party has a full inventory there is no reason to scavenge. Stopping for useless grenades and/or throwing those grenades will extend the length of the run, causing more SI and zombie hordes to spawn. Think of grenades as outs you have for tough situations, not as an extension of your ammo clip.

5. Fallen Survivors (The Passing) have a chance to drop Molotovs, Pipe Bombs, First Aid Kits, and/or Pain Pills. CEDA Agents have a chance to drop Bile Bombs. All of these are visible on the ingame models before you kill them.

6. If you see a crate of Molotovs or Pipe Bombs, you may choose to throw one or two to clear some common out of the way, but don't let it heavily slow you down. Usually it is best to keep moving as long as everybody has a throwable on them.

7. If you're new to the game, carry the Pipe Bomb, and let the other more experienced players carry Molotovs or Bile Bombs. You can't really mess up using a Pipe Bomb, and if you do, the downside isn't going to be that bad. A misused Molotov can mean an unlit tank or a survivor barbecue. A misused Bile Bomb is just frustrating as you waste time and ammo and risk damage or death.

8. Attack priority for common infected is:

• 1) pipe bomb
  
• 2) boomer'd survivor
  
• 3) bile bomb
  
• 4) survivors

Do NOT throw a bile bomb if someone has been puked on by a Boomer!

Common times to use a Molotov:

1. Burning a tank. Makes killing tanks significantly easier as they are on fire and will die eventually over time. The best time to throw a Molotov at a tank is when they are beginning to throw a rock. Another choice is to light up a choke point that the tank must pass through, but be careful as Tanks have ways around most chokes. AI will walk through fire, but human players will wait for it to disappear, find another way around, or start throwing rocks at you. A tank may douse the flames by walking into any pool of water.

2. Burning a witch. Light her up and run the other way! If nobody on your team is capable of crowning, this is the next easiest way of killing a Witch. Set her on fire and just run away until she dies.

3. Burning a choke point. You hear a horde coming. A Molotov here can completely block the infected off on one side. If there is only one approach, then you can use this time to kit, defib, reload or whatever else you might need to do. If there is more than one approach, then you'll still be saving yourself some ammo. You can also choose to fight your way out one side while an other side is protected by the Molotov.

Uncommon times to use a Molotov:

4. Burning an open area (non-choke). Usually done in desperation in order to get incapacitated teammates up. If you can cut the flow of commons down to something that your buddy's pistols can handle, then this maneuver can be worth it. Similar to #3, but much less effective use of a Molotov. Try to pay attention to where the horde are coming, look out for spots where they tend to funnel or perhaps walls or drops they have to traverse.

Rare times to use a Molotov:

5. Breaking a tank's rock throw. Highly advanced technique not suggested for anybody. Only useful if you're out of ammo to skeet rocks with and have no melee weapon to swing at it, and limping so you cannot strafe dodge it.

6. Intercepting a witch. Another highly advanced technique that you will rarely see. Your teammate pissed a witch off by being too close to it. Before a shot is fired, he's already running for his life. If the witch catches fire first then she will chase you instead. She must be lit by you before she is hit by anybody else.

Things to be aware of:

1. The fire from Molotovs take a while to dissipate. When a thrown Molotov confines a team, keep in mind you're slowing things down, the longer you dwindle, the more you risk extra SI/horde spawning. Because of this, don't throw Molotovs frivolously, especially to the point of slowing down your team.

2. Gas tanks, like Molotovs, produce fire on the spot, but must be shot to ignite first. Gas tanks will also explode if they are in a fire. They can be thrown using right click, or even further using left+right click successively. They can be shot in the air but not while being held.

3. Molotovs hurt! While on Easy/Normal mode you can simply run through fire, or throw a Molotov at your own feet to escape a horde, this isn't suggested on Advanced/Realism mode. Don't stand in the fire.

4. Molotovs against other standard SI will make them eventually burn to death. Its nice to occasionally get an SI kill from a thrown Molotov, but do not throw Molotovs at SI to kill them, use other means.

5. Fires don't care about most walls or corners, so you can use this to your advantage whether you're burning zombie hordes or trying to get a tank lit.

6. It can be difficult to see through fire, be careful of problems created by separation.

7. CEDA Agent uncommon infected are immune to fire. Any common lit on fire will wander aimlessly until they die. All SI can still attack you, including Witches and Tanks.

Common times to use a Pipe Bomb:

1. You've just been boomed on or a natural horde has spawned and you can't afford to take any damage from common.
2. Somebody is incapacitated and needs to be helped up.
3. Somebody is black and white and needs to use a first aid kit.
4. Somebody needs to be defib'd during a horde.
5. Running through an area and past a horde.
6. During a Finale when rescue arrives.
7. When you find an extra Pipe Bomb.

Any of the above circumstances can overlap with one another. In general, Pipes are used offensively to clear open areas or run past hordes, or defensively in order to save teammates.

Uncommon times to use a Pipe Bomb:

1. Stumbling a witch off a ledge. It isn't hard to pull off, but you just rarely see a witch next to a ledge, aside from maybe No Mercy_4.

2. Stubborn SI who wont come around a corner. Pipes can stun them allowing you to go in with less risk.

Rare times to use a Pipe Bomb:

1. Stunning a tank. You will rarely be in a position where knowing this play will save you, but it could happen. You can use the 2 seconds it buys you to get a melee swing in or to run further away.

2. Clearing SI from yourself or your teammates. The explosion from a Pipe Bomb will stumble any SI off of survivors. Its nearly always better to shove or kill the SI, but sometimes you're caught holding a Pipe in your hand and upon turning a corner you see an SI but don't have time to switch weapons. I have also used this one time to free a teammate who was far away from me when I was out of primary ammo and using melee weapon as a secondary.

Things to be aware of:

1. Pipes start ticking from the moment you throw them. This means you typically want to throw these short distances or perhaps immediately onto the ground. The more time the bomb spends in the air, the less time the zombies have to group up around it. Zombies tend to be stupid, and they will climb over objects instead of around them sometimes, reducing effectiveness of Pipe Bombs in obstacle clustered spots. Some zombies who are already attacking survivors will not become interested in Pipe Bombs until they are shoved away.

2. Pipe Bombs will set off alarm cars if thrown too close. Pipe Bomb damage can also set off Witches and ignitable objects (which can also set off Witches). Pipes also do friendly fire damage. The damage tends to be insignificant but you still want to be careful.

3. When running, remember that Pipe Bombs last shorter than Bile Bombs and are not as effective to use. If you have a choice, use a Bile Bomb first and save Pipe for emergency. You want to always have a Pipe on your team for emergencies.

4. Common will follow Pipes off of bridges and ledges to their death in some locations. If you throw a pipe bomb out of bounds or where AI cannot navigate, then the common will become immobilized. This is generally undesirable because the point of a pipe bomb is to kill common, but it can still be slightly useful at times. Immobilized horde will not attack you for the duration of the pipe bomb so you can slip past a large group.

5. The city worker uncommon infected ignore Pipe Bombs.

Common times to throw a Bile:

1. To bypass a horde in an open area. Throw a bile off your main path to draw out common. Use this time to run past open areas that would've otherwise been time consuming or somewhat difficult to clear. Sometimes very useful at the end of a level to reach a safe room.

2. To bypass a horde during an event. During a panic event, such as Dead Center_3 where you must run to turn an alarm off. Also such as The Passing_2, or Dark Carnival_4 where you are trying to reach the saferoom.

3. End of finale to reach rescue vehicle.

Uncommon times to throw a Bile:

1. You're fighting a tank and many common have spawned from a horde or because you had to kite the tank forward. You might also be fighting a tank during a panic event, such as the one on Dead Center_3. Using a bile during a tank fight is unnecessary most of the time, but very rarely it can be helpful.

2. You need to get somebody up or use a kit, nobody has been Boomer'd on, and nobody has a Pipe Bomb to throw instead. Can be useful if someone goes down during an event or horde as a way to concentrate all the infected coming in.

3. You want the Septic Tank achievement. Although I suggest you just hop into any single player or easy mode game to get this achievement, it isn't an unreasonable request in a regular game either, I suppose.

Things to keep in mind:

1. Unlike the other two throwables, this one doesn't actually kill any common, in fact, it spawns more. It does not simply draw out all the nearby common that would've otherwise been in front of your path, as I have seen some new players assert, it creates more out of line of sight that rush in. In order to use this to your advantage you should understand that there is a maximum number of zombies that can be spawned at anytime on a given map, and that wanderers, zombie hordes and SI will spawn at regular intervals. If you throw a Bile Bomb and then don't move, you are allowing SI to respawn, and you will have to fight a large portion of those infected again when they respawn further along the map. Do NOT throw bile bombs frivolously.

2. Using a Bile Bomb is a signal to run. There really is no situation where you want to sit there and kill all the common you just created from a bile bomb. Whenever possible, you don't want to kill any of the common it spawns.

3. It is generally a terrible idea to throw a bile bomb at a Tank, because you now have to deal with the horde you've spawned, making the fight more difficult. The zombies coming from multiple sides have the potential to cause difficulties in kiting, especially in more confined spaces, leading to survivors taking punch or rock damage. Throwing a bile at a lit Tank is useless, and against an unlit Tank, you should be unloading all your rounds into it. If you spawn a horde, the zombies will inevitably soak up your ammo. Bile Bombs blind the infected, but the notion of AI being blinded in an FPS is somewhat ludicrous. You can make your own decision there, but I can't really tell the difference, and AI Tanks are already easily killed via kiting. Bile Bombs get more attention in versus mode where humans control infected, but even then, most players eventually get used to playing through bile covered screens, and can still receive voice communication from teammates.

4. Throwing a Bile at a Witch will piss her off. There are many ways to kill Witches, none suggest using Bile Bombs.

5. Like with Pipes, common will chase Bile Bombs to their death at some map locations. Throwing a bile out of bounds or in a place where the AI cannot navigate will cause all the common to become immobilized. This can be incredibly useful during horde events because it causes less, or none of the horde to spawn.

6. The bomb will break on the first thing it comes in contact with so make sure you don't have common in front of you when you're throwing. Aim higher to throw further and keep in mind where you throw the bile and what directions the zombies will be rushing from. You typically want to throw them off of your 'main path' so that you have plenty of room to run past. If a survivor stands in a bile bomb cloud (or has a bile bomb thrown on them), then they will take damage from the common swinging at the green gases.

7. Although throwing a Molotov onto a Bile Bomb seems logical, it is usually unnecessary. If you want to kill the common, you can use secondary weapons (or waste ammo). If you want to avoid the common, then just run and save the Molotov for something else. It can be useful if you're out of ammo and in a pinch during a horde or panic event where you must camp. Remember that killing the common attracted to a bile bomb will just cause more common to be spawned as long as the bile is still active on the field. Its generally better to keep the horde behind you while you run forward.

8. Never throw a Bile Bomb AFTER a crescendo is over. It will spawn more infected that you just worked so hard to stop. There are also "quiet" periods where nothing will spawn until you pass a certain point in the map. For example, after Whitaker opens the door for you and instructs you to fetch his cola, no horde will spawn until you start the event. When fighting the first tank on the Cold Stream finale, if you had to kite the tank backwards, horde will not spawn until you've approached the tunnel again (or if you wait too long).

9. City workers will ignore Bile Bombs if an Infected is not directly hit by the grenade.

Generally speaking, these objects are unnecessary and can be annoying to set up properly, but if done efficiently can save you time and ammo which can make a world of difference on the higher difficulty settings. You can also throw these objects in the air and shoot them, which essentially mimics a complicated grenade. Fighting the Tank in the boxcar on The Sacrifice_1 is usually the time where most players first discover the usefulness of these items. You can easily go through all maps of the game on all difficulties without ever using any of these, but here are some things you should know!

Gas Cans/Fireworks - Creates fire when shot or in fire. Fireworks also light up enemies but without as much vision obstruction.
Common Uses:
1. Most players use these exactly as you would a Molotov. They are effective against Tanks, Witches, and at eliminating common at a choke.
2. During Finales or other horde events to control the number and direction of infected. Either spread them all around you or keep a pile of them near you and throw one or two down each wave.
3. Scavenge Finales (Dead Center, The Passing). If you bring some with you from a previous round you can pour them into the car/generator and save some time. If a gas can required for a Scavenge Finale explodes, you must wait for the fire to go out for the can to respawn in its original location.
4. In Versus Mode, placing a gas can in a spot will usually discourage a player controlling a Tank to go that direction. You don't even need to light it, just its presence is enough to deter most Tanks.
Note: In Scavenge Mode games, enemy Spitters can ignite your team's gas cans with their spit attack if they've been picked up by you before (yellow outlines as opposed to white outlines).

Propane Tank - Explosion is similar to that of a Pipe Bomb, but there is no ticking to attract nearby common.
Oxygen Tank - Similar to Propane Tank, except explosion is delayed and has a smaller area of effect. The Oxygen Tank is also much harder to see and shoot. Shotguns can explode an Oxygen Tank in one shot.
Practical Uses:
1. Place at a choke point or in an open area and shoot when multiple common are nearby.
2. Place at a choke point to stumble a tank. For example, if you can manage to stumble a Tank who just exits a building, you give your team ample time to either find safety, unload their magazines into him, or even get in a few melee hits.
3. Stumbling a Tank or a Witch off a ledge. No Mercy_4 Rooftops, usually. Very rare to see.
4. If your ally has an SI on him and there are common beating on him, then you can sometimes use a Propane Tank to kill all the common and free him at the same time. Usually there will be better ways to do this than using friendly fire, but it can be a valid option under the right circumstance.
5. Stumbling a Witch off of an ally. This will do friendly fire damage but hopefully you can kill the Witch in time and save your ally.
6. Get a whole bunch of them together for a chain reaction, which can lead to massive damage and a really easy Tank fight.
7. To eliminate a horde on a Bile Bomb.

Just as my First Aid Kit guide, the information here reflects the many combined years of experience in the Left 4 Dead community. The hayday of Left 4 Dead 2 seems to be gone, and with it, many of the most knowledgeable, experienced and skilled players, and the cesspool remaining is very unfriendly to most new players, which only further exacerbates the problem. I want to help rebuild a playerbase and I hope that my guides can help players both old and new learn effective means of playing the game.

That said, this game is highly adaptive. The director changes the game based on your performance. This means you could play nearly any way you wanted to and still win. I am not here to rain on people's parades or tell them how they need to play the game, I am merely pointing out facts about game mechanics, options for strategy, and opinions on efficiency. The advice in here is sound and will get you far in public games or while playing with your friends.

If I'm missing any other common uses of these throwables, please feel free to let me know down below in the comments section, along with any other feedback.

If you're interested in translating this guide into your language, please contact me first.

If you agree with the guide, please rate up, help spread the information about Proper Throwables Usage to make those public games safer and more enjoyable!

9/13/2014 : version 1.04 (minor updates)
3/6/2013 : version 1.03 (minor edits)
2/28/2013 : version 1.02 (added ignitable objects)
2/27/2013 : version 1.01 (corrections)
2/23/2013 : version 1.00