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.
Survive all campaigns on Expert.
Survive a campaign on Expert skill with Realism mode enabled.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Cause 25 gas can drops as a Special Infected.
Defend yourself at the crashed airliner without taking damage.
Make a Survivor drop a gas can during overtime.
As the Charger, bowl through the entire enemy team in a single charge.
Collect 100 gas cans in Scavenge.
In a Survival round, get a medal only using melee weapons.
Cross the bridge finale in less than three minutes.
As the Charger, grab a Survivor and carry them over 80 feet.
Revive 10 dead Survivors with the defibrillator.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Kill a Tank with melee weapons.
Win a game of Scavenge.
Collect 15 gas cans in a single Scavenge round.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Kill a Charger with a melee weapon while they are charging.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Spread cheer by helping a free holiday player survive a campaign.
Finish a campaign using only melee weapons.
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.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Survive the Swamp Fever campaign.
Kill 10 swampy Mudmen while they are in the water.
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.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Ignite 50 Common Infected with incendiary ammo.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Spitter, hit every Survivor with a single acid patch.
Honk the noses of 10 Clowns.
Prove you are stronger than Moustachio.
Plays games with free weekend players and helps them survive a campaign.
Survive the Dark Carnival campaign.
Rescue Gnome Chompski from the Carnival.
Kill one of each Uncommon Infected.
Prove you are faster than Moustachio.
Survive the Parish campaign.
Kill 100 Common Infected with the chainsaw.
Use every melee weapon to kill Common Infected.
Survive the Hard Rain campaign.
Decapitate 200 Infected with a melee weapon.
Survive the Dead Center campaign.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Kill 15 Infected with a single grenade launcher blast.
Kill a Spitter before she is able to spit.
Use a bile bomb on a Tank.
Deploy an ammo upgrade and have your team use it.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play 6 Mutations.
Play 5 full games of Scavenge on The Port.
Collect 10 items dropped by a Fallen Survivor.
Open 5 foot lockers.
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.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Kill a Special Infected with an exploding barrel.
Have all 3 generators running at once in "The Sacrifice" finale.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".
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
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Survive for 10 minutes on any official map in Versus Survival.
Kill 20 Jockeys with the shovel or pitchfork.
As the Hunter, land a 25 damage pounce.
Kill the Witch bride with a single shotgun blast on expert difficulty.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Rescue three Survivors from a single rescue closet.
Kill a pouncing Hunter with a shotgun.
Destroy 20 gascans as the Spitter.
Destroy a Tank's rock in mid-air.
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.
Escape Liberty Mall's Atrium before the first Tank appears
On the concert finale, survive until the helicopter arrives without leaving the stage
Survive The Last Stand campaign on Expert Realism.
Revive an incapacitated teammate while a Tank is nearby.
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 Boomer, vomit on a Survivor without having direct line of sight with them.
Discover the hidden room in the Last Stand campaign
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Survive The Last Stand campaign on any difficulty.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.