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