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.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
As the Charger, bowl through the entire enemy team in a single charge.
Collect 100 gas cans in Scavenge.
As the Spitter, spit on a Survivor being choked by a Smoker.
Cause 25 gas can drops as a Special Infected.
Make a Survivor drop a gas can during overtime.
As the Charger, grab a Survivor and carry them over 80 feet.
Collect 15 gas cans in a single Scavenge round.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Win a game of Scavenge.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Honk the noses of 10 Clowns.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
As the Jockey, ride the Survivors twice in a single life.
As the Spitter, hit every Survivor with a single acid patch.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Rescue Gnome Chompski from the Carnival.
Prove you are stronger than Moustachio.
Kill a Charger with a melee weapon while they are charging.
Survive a campaign on Expert skill with Realism mode enabled.
Revive 10 dead Survivors with the defibrillator.
Defend yourself at the crashed airliner without taking damage.
Survive all campaigns on Expert.
Cross the bridge finale in less than three minutes.
Kill 15 Infected with a single grenade launcher blast.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
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 smash them into the ground for a solid 15 seconds.
As the Jockey, ride a Survivor for more than 12 seconds.
Finish a campaign using only melee weapons.
Kill 10 swampy Mudmen while they are in the water.
Deploy an ammo upgrade and have your team use it.
Survive the Swamp Fever campaign.
Plays games with free weekend players and helps them survive a campaign.
Use every melee weapon to kill Common Infected.
Kill a Tank with melee weapons.
Kill 100 Common Infected with the chainsaw.
Ignite 50 Common Infected with incendiary ammo.
Use a bile bomb on a Tank.
Decapitate 200 Infected with a melee weapon.
Survive the Parish campaign.
Survive the Hard Rain campaign.
Kill one of each Uncommon Infected.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Survive the Dark Carnival campaign.
Kill a Spitter before she is able to spit.
Prove you are faster than Moustachio.
Spread cheer by helping a free holiday player survive a campaign.
Survive the Dead Center campaign.
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.
Using the M60, kill 25 infected without letting go of the trigger.
Collect 10 items dropped by a Fallen Survivor.
Open 5 foot lockers.
Play 6 Mutations.
Knock off the heads of 18 infected with the golf club.
Kill a Tank only with damage from the original Survivors.
Survive The Passing Campaign.
Play the new Midnight Riders song on a jukebox.
Have all 3 generators running at once in "The Sacrifice" finale.
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.
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
Escape Liberty Mall's Atrium before the first Tank appears
Survive The Last Stand campaign on Expert Realism.
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 a pouncing Hunter with a shotgun.
Kill the Witch bride with a single shotgun blast on expert difficulty.
As the Hunter, land a 25 damage pounce.
Kill 20 Jockeys with the shovel or pitchfork.
Destroy a Tank's rock in mid-air.
Survive for 10 minutes on any official map in Versus Survival.
Survive for 30 minutes on any official survival map.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Destroy 20 gascans as the Spitter.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
As the Spitter, spit on a Survivor who is pinned by a Charger.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
Instantly kill a Survivor as the Charger.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
Earn a gold medal on any official survival map.
Revive an incapacitated teammate while a Tank is nearby.
Earn a silver medal on any official survival map.
Earn a bronze medal on any official Survival map.
On the concert finale, survive until the helicopter arrives without leaving the stage
Survive The Last Stand campaign on any difficulty.
Discover the hidden room in the Last Stand campaign
Rescue three Survivors from a single rescue closet.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.