Molotov Cocktail

The Molotov cocktail is a thrown weapon that engulfs an area with flames for a short time. The area of effect is quite large and spreads over time before self-extinguishing. The fire will burn all Infected that come into contact with it. While Common Infected cannot attack after being ignited and die in seconds, Special Infected can withstand the fire until their health is burned away. The Molotov cocktail is dangerous in close combat because the splash damage and flames may cause you and nearby teammates to lose health.

Tactics

 * If a Boomer is around a corner where the wall is impenetrable by bullets, and you do not wish to risk being covered in bile by attempting to land a well-angled shot; throw a Molotov around the corner. The flames will spread, so it is not required to hit him directly in order to kill him.
 * Do not hit teammates. If they are incapacitated inside a fire, it may be difficult to revive them.
 * Where the Pipe bomb is less effective (e.g. against bosses) due to its fuse, the Molotov shines. Setting a Witch on fire will gradually burn her health away, making her easier to kill. A burning Tank will survive for 40 seconds at most.
 * No Infected of any kind know better than to avoid fire, and will gladly cross it to reach you. The crux of the Molotov strategy is to let them. If you know where a Horde is coming from, throw the Molotov at a choke point between the Horde and your teammates. The flaming barrier will burn all Common Infected as they try to cross it.  Try to throw the Molotov just as they reach the choke point in order to increase the likelihood of burning the entire Horde before the flames expire.  NOTE sometimes they will try to find a way around the fire
 * Obviously, fire does not burn in water.
 * There is at least one exception to this: Death Toll's first crescendo point in the storm drains. A molotov thrown into the shallow water will burn as normal.
 * Once lit, Special Infected do not self-extinguish. They will burn until they die. This applies for Tanks and Witches, too.
 * In Versus, if a player is hanging and being attacked by a smoker out of reach from normal weapons, consider lobbing a molotov to release them.
 * If you are in a bad mood, you can, when the Tank comes, throw the Molotov in a choke point before your teammates get through to let the Tank kill them while you run to the safe house. Just be wary of the bad karma that follows!

Infected

 * Though it will eventually kill it, the Hunter does twice the normal damage when it is on fire. NOTE: After the recent update, the bonus fire damage is only gained by lighting a Hunter on fire using a molotov. The Hunter doesn't deal as much damage as it used to after the update as well.
 * As a Boomer, you can set yourself on fire to become a ticking time bomb. Run into survivors to forcefully explode, since the survivors can't safely push you away and shoot you without the risk of being exploded on.
 * If you're playing as a Smoker, a great tactic is to drag a survivor through the flames, causing massive damage and preventing others from, rescuing them.