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.
As the Spitter, spit on a Survivor being choked by a Smoker.
Spread cheer by helping a free holiday player survive a campaign.
As the Charger, bowl through the entire enemy team in a single charge.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Survive a campaign on Expert skill with Realism mode enabled.
Survive all campaigns on Expert.
Cause 25 gas can drops as a Special Infected.
Revive 10 dead Survivors with the defibrillator.
Kill a Tank with melee weapons.
Kill a Charger with a melee weapon while they are charging.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Collect 100 gas cans in Scavenge.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Survive the Swamp Fever campaign.
Cross the bridge finale in less than three minutes.
Survive the Parish campaign.
Defend yourself at the crashed airliner without taking damage.
Kill 10 swampy Mudmen while they are in the water.
Prove you are stronger than Moustachio.
Plays games with free weekend players and helps them survive a campaign.
In a Survival round, get a medal only using melee weapons.
Finish a campaign using only melee weapons.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
Make a Survivor drop a gas can during overtime.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Ignite 50 Common Infected with incendiary ammo.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Survive the Hard Rain campaign.
Navigate the sugar mill and reach the safe room without killing any Witches.
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 Charger, grab a Survivor and carry them over 80 feet.
Win a game of Scavenge.
Collect 15 gas cans in a single Scavenge round.
As the Jockey, ride a Survivor for more than 12 seconds.
Survive the Dark Carnival campaign.
Honk the noses of 10 Clowns.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Kill 15 Infected with a single grenade launcher blast.
Use every melee weapon to kill Common Infected.
Survive the Dead Center campaign.
Kill 100 Common Infected with the chainsaw.
Decapitate 200 Infected with a melee weapon.
Rescue Gnome Chompski from the Carnival.
Prove you are faster than Moustachio.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Use a bile bomb on a Tank.
Deploy an ammo upgrade and have your team use it.
Kill a Spitter before she is able to spit.
Kill one of each Uncommon Infected.
Play 5 full games of Scavenge on The Port.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Kill a Tank only with damage from the original Survivors.
Play the new Midnight Riders song on a jukebox.
Play 6 Mutations.
Using the M60, kill 25 infected without letting go of the trigger.
Survive The Passing Campaign.
Knock off the heads of 18 infected with the golf club.
Open 5 foot lockers.
Collect 10 items dropped by a Fallen Survivor.
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.
Have all 3 generators running at once in "The Sacrifice" finale.
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.
Survive for 10 minutes on any official map in Versus Survival.
Destroy 20 gascans as the Spitter.
Escape Liberty Mall's Atrium before the first Tank appears
Survive The Last Stand campaign on Expert Realism.
Earn a gold medal on every official survival map.
Earn a bronze medal on every official survival map
Earn a silver medal on every official survival map.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Kill 20 Jockeys with the shovel or pitchfork.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
As the Hunter, land a 25 damage pounce.
As the Spitter, spit on a Survivor who is pinned by a Charger.
Instantly kill a Survivor as the Charger.
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 Hunter.
Discover the hidden room in the Last Stand campaign
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
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
Kill a pouncing Hunter with a shotgun.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Survive The Last Stand campaign on any difficulty.
Destroy a Tank's rock in mid-air.
Revive an incapacitated teammate while a Tank is nearby.
Rescue three Survivors from a single rescue closet.
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.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.