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.
Plays games with free weekend players and helps them survive a campaign.
Kill a Charger with a melee weapon while they are charging.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Survive a campaign on Expert skill with Realism mode enabled.
As the Charger, bowl through the entire enemy team in a single charge.
Finish a campaign using only melee weapons.
Cause 25 gas can drops as a Special Infected.
Kill 15 Infected with a single grenade launcher blast.
Collect 100 gas cans in Scavenge.
In a Survival round, get a medal only using melee weapons.
As the Charger, grab a Survivor and carry them over 80 feet.
Make a Survivor drop a gas can during overtime.
Revive 10 dead Survivors with the defibrillator.
Survive all campaigns on Expert.
Cross the bridge finale in less than three minutes.
Survive the Parish campaign.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
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.
Win a game of Scavenge.
Stop the enemy team from collecting any gas cans during a Scavenge round.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Spitter, hit every Survivor with a single acid patch.
As the Jockey, ride the Survivors twice in a single life.
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.
Navigate the sugar mill and reach the safe room without killing any Witches.
Kill a Tank with melee weapons.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Spread cheer by helping a free holiday player survive a campaign.
Survive the Hard Rain campaign.
Survive the Swamp Fever campaign.
Defend yourself at the crashed airliner without taking damage.
Kill 10 swampy Mudmen while they are in the water.
Kill one of each Uncommon Infected.
Rescue Gnome Chompski from the Carnival.
Prove you are faster than Moustachio.
Prove you are stronger than Moustachio.
Honk the noses of 10 Clowns.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Survive the Dark Carnival campaign.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Kill 100 Common Infected with the chainsaw.
Use every melee weapon to kill Common Infected.
Use a bile bomb on a Tank.
Decapitate 200 Infected with a melee weapon.
Ignite 50 Common Infected with incendiary ammo.
Kill a Spitter before she is able to spit.
Survive the Dead Center campaign.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
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.
Open 5 foot lockers.
Kill a Tank only with damage from the original Survivors.
Play 5 full games of Scavenge on The Port.
Using the M60, kill 25 infected without letting go of the trigger.
Play 6 Mutations.
Knock off the heads of 18 infected with the golf club.
Collect 10 items dropped by a Fallen Survivor.
Play the new Midnight Riders song on a jukebox.
Survive The Passing Campaign.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".
Have all 3 generators running at once in "The Sacrifice" finale.
Kill a Special Infected with an exploding barrel.
As a Special Infected, incap someone who is trying to sacrifice themselves.
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!
Survive The Last Stand campaign on Expert Realism.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Survive The Last Stand campaign on any difficulty.
Discover the hidden room in the Last Stand campaign
On the concert finale, survive until the helicopter arrives without leaving the stage
Escape Liberty Mall's Atrium before the first Tank appears
Survive for 30 minutes on any official survival map.
Earn a gold medal on every official survival map.
Earn a silver medal on every official survival map.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Kill 20 Jockeys with the shovel or pitchfork.
Destroy 20 gascans as the Spitter.
Rescue three Survivors from a single rescue closet.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
As the Hunter, land a 25 damage pounce.
As the Spitter, spit on a Survivor who is pinned by a Charger.
Earn a bronze medal on every official survival map
Earn a gold medal on any official survival map.
Survive for 10 minutes on any official map in Versus Survival.
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.
Destroy a Tank's rock in mid-air.
Kill a pouncing Hunter with a shotgun.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
Revive an incapacitated teammate while a Tank is nearby.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
Instantly kill a Survivor as the Charger.
Earn a silver medal on any official survival map.
Earn a bronze medal on any official Survival map.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.