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.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Cause 25 gas can drops as a Special Infected.
Survive all campaigns on Expert.
Collect 100 gas cans in Scavenge.
Plays games with free weekend players and helps them survive a campaign.
Survive a campaign on Expert skill with Realism mode enabled.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Cross the bridge finale in less than three minutes.
Defend yourself at the crashed airliner without taking damage.
Prove you are stronger than Moustachio.
Rescue Gnome Chompski from the Carnival.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Prove you are faster than Moustachio.
As the Charger, grab a Survivor and carry them over 80 feet.
Kill 15 Infected with a single grenade launcher blast.
Spread cheer by helping a free holiday player survive a campaign.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
Revive 10 dead Survivors with the defibrillator.
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.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Charger, bowl through the entire enemy team in a single charge.
Kill 10 swampy Mudmen while they are in the water.
As the Spitter, hit every Survivor with a single acid patch.
Survive the Hard Rain campaign.
Survive the Parish campaign.
In a Survival round, get a medal only using melee weapons.
Win a game of Scavenge.
Ignite 50 Common Infected with incendiary ammo.
Kill 100 Common Infected with the chainsaw.
Honk the noses of 10 Clowns.
Use a bile bomb on a Tank.
As the Jockey, ride a Survivor for more than 12 seconds.
As the Jockey, ride the Survivors twice in a single life.
Collect 15 gas cans in a single Scavenge round.
Make a Survivor drop a gas can during overtime.
Survive the Swamp Fever campaign.
Survive the Dark Carnival campaign.
Deploy an ammo upgrade and have your team use it.
Survive the Dead Center campaign.
Finish a campaign using only melee weapons.
Kill a Charger with a melee weapon while they are charging.
Decapitate 200 Infected with a melee weapon.
Use every melee weapon to kill Common Infected.
Kill one of each Uncommon Infected.
Kill a Spitter before she is able to spit.
Kill a Tank with melee weapons.
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.
Play the new Midnight Riders song on a jukebox.
Collect 10 items dropped by a Fallen Survivor.
Knock off the heads of 18 infected with the golf club.
Play 6 Mutations.
Open 5 foot lockers.
Survive The Passing Campaign.
Kill a Tank only with damage from the original Survivors.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Have all 3 generators running at once in "The Sacrifice" finale.
Complete "The Sacrifice".
Have Bill sacrifice himself for the team.
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.
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.
Survive The Last Stand campaign on Expert Realism.
Kill 20 Jockeys with the shovel or pitchfork.
As the Hunter, land a 25 damage pounce.
Kill 53,599 infected. You made sure the dead won't rise anymore!
On the concert finale, survive until the helicopter arrives without leaving the stage
Escape Liberty Mall's Atrium before the first Tank appears
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
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.
Destroy a Tank's rock in mid-air.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
Destroy 20 gascans as the Spitter.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Survive for 30 minutes on any official survival map.
Kill a pouncing Hunter with a shotgun.
Survive The Last Stand campaign on any difficulty.
Discover the hidden room in the Last Stand campaign
Earn a bronze medal on every official survival map
Instantly kill a Survivor as the Charger.
Survive for 10 minutes on any official map in Versus Survival.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Rescue three Survivors from a single rescue closet.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
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.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.