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.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Defend yourself at the crashed airliner without taking damage.
Spread cheer by helping a free holiday player survive a campaign.
Plays games with free weekend players and helps them survive a campaign.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
In a Survival round, get a medal only using melee weapons.
Finish a campaign using only melee weapons.
Navigate the sugar mill and reach the safe room without killing any Witches.
Kill a Tank with melee weapons.
Survive a campaign on Expert skill with Realism mode enabled.
Survive all campaigns on Expert.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Prove you are faster than Moustachio.
Rescue Gnome Chompski from the Carnival.
Cause 25 gas can drops as a Special Infected.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Collect 100 gas cans in Scavenge.
Make a Survivor drop a gas can during overtime.
Prove you are stronger than Moustachio.
Kill 100 Common Infected with the chainsaw.
Kill 10 swampy Mudmen while they are in the water.
As the Charger, bowl through the entire enemy team in a single charge.
Decapitate 200 Infected with a melee weapon.
Revive 10 dead Survivors with the defibrillator.
Kill 15 Infected with a single grenade launcher blast.
Use every melee weapon to kill Common Infected.
Ignite 50 Common Infected with incendiary ammo.
Honk the noses of 10 Clowns.
As the Spitter, hit every Survivor with a single acid patch.
Win a game of Scavenge.
Collect 15 gas cans in a single Scavenge round.
Survive the Dead Center campaign.
Survive the Hard Rain campaign.
Survive the Swamp Fever campaign.
Kill one of each Uncommon Infected.
Survive the Dark Carnival campaign.
Use a bile bomb on a Tank.
Cross the bridge finale in less than three minutes.
Survive the Parish campaign.
Kill a Charger with a melee weapon while they are charging.
Deploy an ammo upgrade and have your team use it.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Charger, grab a Survivor and carry them over 80 feet.
Kill a Spitter before she is able to spit.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Jockey, ride the Survivors twice in a single life.
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.
Play 5 full games of Scavenge on The Port.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Using the M60, kill 25 infected without letting go of the trigger.
Play 6 Mutations.
Collect 10 items dropped by a Fallen Survivor.
Knock off the heads of 18 infected with the golf club.
Kill a Tank only with damage from the original Survivors.
Play the new Midnight Riders song on a jukebox.
Open 5 foot lockers.
Survive The Passing Campaign.
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 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 for 30 minutes on any official survival map.
On the concert finale, survive until the helicopter arrives without leaving the stage
Survive The Last Stand campaign on Expert Realism.
Escape Liberty Mall's Atrium before the first Tank appears
Destroy 20 gascans as the Spitter.
Rescue three Survivors from a single rescue closet.
Kill 20 Jockeys with the shovel or pitchfork.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
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.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Instantly kill a Survivor as the Charger.
Survive for 10 minutes on any official map in Versus Survival.
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.
Discover the hidden room in the Last Stand campaign
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 Boomer, vomit on a Survivor without having direct line of sight with them.
As the Hunter, land a 25 damage pounce.
Kill a pouncing Hunter with a shotgun.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
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.