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