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