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.
Cause 25 gas can drops as a Special Infected.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
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.
Collect 100 gas cans in Scavenge.
Kill a Charger with a melee weapon while they are charging.
Revive 10 dead Survivors with the defibrillator.
As the Charger, bowl through the entire enemy team in a single charge.
As the Spitter, spit on a Survivor being choked by a Smoker.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Finish a campaign using only melee weapons.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Cross the bridge finale in less than three minutes.
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.
Kill a Tank with melee weapons.
In a Survival round, get a medal only using melee weapons.
Win a game of Scavenge.
Spread cheer by helping a free holiday player survive a campaign.
Make a Survivor drop a gas can during overtime.
Stop the enemy team from collecting any gas cans during a Scavenge round.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
As the Charger, grab a Survivor and carry them over 80 feet.
Collect 15 gas cans in a single Scavenge round.
Kill 10 swampy Mudmen while they are in the water.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Rescue Gnome Chompski from the Carnival.
Plays games with free weekend players and helps them survive a campaign.
Honk the noses of 10 Clowns.
As the Jockey, ride a Survivor for more than 12 seconds.
As the Jockey, ride the Survivors twice in a single life.
As the Spitter, hit every Survivor with a single acid patch.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Survive the Parish campaign.
Ignite 50 Common Infected with incendiary ammo.
Use every melee weapon to kill Common Infected.
Survive the Swamp Fever campaign.
Defend yourself at the crashed airliner without taking damage.
Survive the Dark Carnival campaign.
Prove you are stronger than Moustachio.
Prove you are faster than Moustachio.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Kill 15 Infected with a single grenade launcher blast.
Survive the Dead Center campaign.
Kill 100 Common Infected with the chainsaw.
Survive the Hard Rain campaign.
Use a bile bomb on a Tank.
Kill one of each Uncommon Infected.
Decapitate 200 Infected with a melee weapon.
Kill a Spitter before she is able to spit.
Deploy an ammo upgrade and have your team use it.
Play 5 full games of Scavenge on The Port.
Open 5 foot lockers.
Collect 10 items dropped by a Fallen Survivor.
Kill a Tank only with damage from the original Survivors.
Knock off the heads of 18 infected with the golf club.
Play 6 Mutations.
Using the M60, kill 25 infected without letting go of the trigger.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Play the new Midnight Riders song on a jukebox.
Survive The Passing Campaign.
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.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".
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 for 30 minutes on any official survival map.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Survive The Last Stand campaign on Expert Realism.
Escape Liberty Mall's Atrium before the first Tank appears
Rescue three Survivors from a single rescue closet.
On the concert finale, survive until the helicopter arrives without leaving the stage
Survive The Last Stand campaign on any difficulty.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Earn a gold medal on any official survival map.
Survive for 10 minutes on any official map in Versus Survival.
Earn a silver medal on any official survival map.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
Discover the hidden room in the Last Stand campaign
Kill 20 Jockeys with the shovel or pitchfork.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Kill a pouncing Hunter with a shotgun.
Earn a bronze medal on any official Survival map.
Instantly kill a Survivor as the Charger.
Revive an incapacitated teammate while a Tank is nearby.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
As the Spitter, spit on a Survivor who is pinned by a Charger.
As the Hunter, land a 25 damage pounce.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
Destroy a Tank's rock in mid-air.
Destroy 20 gascans as the Spitter.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.