Full list of all 101 Left 4 Dead 2 achievements. It takes around 80-100 hours to unlock all of the achievements in the base game on Windows.
The base game contains 52 achievements, and there are 7 DLC packs containing 49 achievements.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Kill a Charger with a melee weapon while they are charging.
Cause 25 gas can drops as a Special Infected.
As the Charger, grab a Survivor and carry them over 80 feet.
As the Charger, bowl through the entire enemy team in a single charge.
As the Jockey, ride the Survivors twice in a single life.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Survive all campaigns on Expert.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Revive 10 dead Survivors with the defibrillator.
Navigate the sugar mill and reach the safe room without killing any Witches.
Cross the bridge finale in less than three minutes.
Defend yourself at the crashed airliner without taking damage.
Rescue Gnome Chompski from the Carnival.
Prove you are stronger than Moustachio.
Honk the noses of 10 Clowns.
Kill 10 swampy Mudmen while they are in the water.
Use every melee weapon to kill Common Infected.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Spitter, hit every Survivor with a single acid patch.
Collect 100 gas cans in Scavenge.
Collect 15 gas cans in a single Scavenge round.
Spread cheer by helping a free holiday player survive a campaign.
Make a Survivor drop a gas can during overtime.
Win a game of Scavenge.
Stop the enemy team from collecting any gas cans during a Scavenge round.
As the Jockey, ride a Survivor for more than 12 seconds.
Prove you are faster than Moustachio.
Kill 15 Infected with a single grenade launcher blast.
Survive a campaign on Expert skill with Realism mode enabled.
Finish a campaign using only melee weapons.
Kill 100 Common Infected with the chainsaw.
Kill a Tank with melee weapons.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
In a Survival round, get a medal only using melee weapons.
Survive the Dark Carnival campaign.
Plays games with free weekend players and helps them survive a campaign.
Survive the Parish campaign.
Survive the Hard Rain campaign.
Decapitate 200 Infected with a melee weapon.
Survive the Swamp Fever campaign.
Kill one of each Uncommon Infected.
Ignite 50 Common Infected with incendiary ammo.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Use a bile bomb on a Tank.
Survive the Dead Center campaign.
Kill a Spitter before she is able to spit.
Deploy an ammo upgrade and have your team use it.
Play 6 Mutations.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Kill a Tank only with damage from the original Survivors.
Knock off the heads of 18 infected with the golf club.
Play 5 full games of Scavenge on The Port.
Using the M60, kill 25 infected without letting go of the trigger.
Collect 10 items dropped by a Fallen Survivor.
Survive The Passing Campaign.
Open 5 foot lockers.
Play the new Midnight Riders song on a jukebox.
Complete "The Sacrifice".
As a Special Infected, incap someone who is trying to sacrifice themselves.
Have all 3 generators running at once in "The Sacrifice" finale.
Kill a Special Infected with an exploding barrel.
Have Bill sacrifice himself for the team.
Survive the Cold Stream campaign on any difficulty.
Play a Versus game on Dead Air from start to finish.
Collect three gifts dropped by Special Infected in Versus Mode.
Kill 53,599 infected. You made sure the dead won't rise anymore!
Survive for 10 minutes on any official map in Versus Survival.
Survive The Last Stand campaign on Expert Realism.
Instantly kill a Survivor as the Charger.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Rescue three Survivors from a single rescue closet.
Discover the hidden room in the Last Stand campaign
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Survive The Last Stand campaign on any difficulty.
Earn a gold medal on every official survival map.
Earn a silver medal on every official survival map.
Earn a bronze medal on every official survival map
Kill 20 Jockeys with the shovel or pitchfork.
On the concert finale, survive until the helicopter arrives without leaving the stage
Kill the Witch bride with a single shotgun blast on expert difficulty.
As the Spitter, spit on a Survivor who is pinned by a Charger.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
As the Hunter, land a 25 damage pounce.
Destroy 20 gascans as the Spitter.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
Kill a pouncing Hunter with a shotgun.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Escape Liberty Mall's Atrium before the first Tank appears
Survive for 30 minutes on any official survival map.
Earn a gold medal on any official survival map.
Earn a silver medal on any official survival map.
Earn a bronze medal on any official Survival map.
Revive an incapacitated teammate while a Tank is nearby.
Destroy a Tank's rock in mid-air.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.