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