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.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Plays games with free weekend players and helps them survive a campaign.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Survive a campaign on Expert skill with Realism mode enabled.
Survive all campaigns on Expert.
Kill a Tank with melee weapons.
Spread cheer by helping a free holiday player survive a campaign.
Revive 10 dead Survivors with the defibrillator.
Collect 100 gas cans in Scavenge.
In a Survival round, get a medal only using melee weapons.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Defend yourself at the crashed airliner without taking damage.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Finish a campaign using only melee weapons.
Cross the bridge finale in less than three minutes.
Navigate the sugar mill and reach the safe room without killing any Witches.
Kill 15 Infected with a single grenade launcher blast.
Cause 25 gas can drops as a Special Infected.
Make a Survivor drop a gas can during overtime.
Kill a Charger with a melee weapon while they are charging.
As the Charger, bowl through the entire enemy team in a single charge.
Rescue Gnome Chompski from the Carnival.
Prove you are faster than Moustachio.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Kill 10 swampy Mudmen while they are in the water.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
As the Spitter, hit every Survivor with a single acid patch.
Prove you are stronger than Moustachio.
As the Spitter, spit on a Survivor being choked by a Smoker.
Win a game of Scavenge.
Collect 15 gas cans in a single Scavenge round.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
Honk the noses of 10 Clowns.
As the Charger, grab a Survivor and carry them over 80 feet.
As the Jockey, ride a Survivor for more than 12 seconds.
Kill 100 Common Infected with the chainsaw.
Decapitate 200 Infected with a melee weapon.
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.
Use a bile bomb on a Tank.
Survive the Parish campaign.
Ignite 50 Common Infected with incendiary ammo.
Use every melee weapon to kill Common Infected.
Survive the Hard Rain campaign.
Kill one of each Uncommon Infected.
Survive the Swamp Fever campaign.
Survive the Dead Center campaign.
Deploy an ammo upgrade and have your team use it.
Survive the Dark Carnival campaign.
Kill a Spitter before she is able to spit.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play 5 full games of Scavenge on The Port.
Kill a Tank only with damage from the original Survivors.
Using the M60, kill 25 infected without letting go of the trigger.
Play 6 Mutations.
Open 5 foot lockers.
Collect 10 items dropped by a Fallen Survivor.
Play the new Midnight Riders song on a jukebox.
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.
Complete "The Sacrifice".
Have Bill sacrifice himself for the team.
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.
Survive for 10 minutes on any official map in Versus Survival.
Escape Liberty Mall's Atrium before the first Tank appears
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Destroy 20 gascans as the Spitter.
Kill 20 Jockeys with the shovel or pitchfork.
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.
As the Hunter, land a 25 damage pounce.
Instantly kill a Survivor as the 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 Spitter, spit on a Survivor who is pinned by a Charger.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Discover the hidden room in the Last Stand campaign
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
On the concert finale, survive until the helicopter arrives without leaving the stage
Destroy a Tank's rock in mid-air.
Rescue three Survivors from a single rescue closet.
Kill a pouncing Hunter with a shotgun.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Survive The Last Stand campaign on any difficulty.
Revive an incapacitated teammate while a Tank is nearby.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.