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.
Survive a campaign on Expert skill with Realism mode enabled.
Collect 100 gas cans in Scavenge.
Collect 15 gas cans in a single Scavenge round.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
In a Survival round, get a medal only using melee weapons.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Cause 25 gas can drops as a Special Infected.
Make a Survivor drop a gas can during overtime.
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.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
As the Charger, bowl through the entire enemy team in a single charge.
As the Charger, grab a Survivor and carry them over 80 feet.
As the Jockey, ride the Survivors twice in a single life.
As the Jockey, ride a Survivor for more than 12 seconds.
As the Spitter, hit every Survivor with a single acid patch.
Win a game of Scavenge.
Stop the enemy team from collecting any gas cans during a Scavenge round.
Survive all campaigns on Expert.
Revive 10 dead Survivors with the defibrillator.
Defend yourself at the crashed airliner without taking damage.
Kill a Tank with melee weapons.
Cross the bridge finale in less than three minutes.
Kill 15 Infected with a single grenade launcher blast.
Navigate the sugar mill and reach the safe room without killing any Witches.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Prove you are stronger than Moustachio.
Prove you are faster than Moustachio.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Honk the noses of 10 Clowns.
Use a bile bomb on a Tank.
Deploy an ammo upgrade and have your team use it.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Kill a Charger with a melee weapon while they are charging.
Decapitate 200 Infected with a melee weapon.
Ignite 50 Common Infected with incendiary ammo.
Rescue Gnome Chompski from the Carnival.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
Kill 100 Common Infected with the chainsaw.
Finish a campaign using only melee weapons.
Use every melee weapon to kill Common Infected.
Survive the Parish campaign.
Survive the Hard Rain campaign.
Kill one of each Uncommon Infected.
Survive the Swamp Fever campaign.
Kill 10 swampy Mudmen while they are in the water.
Survive the Dark Carnival campaign.
Kill a Spitter before she is able to spit.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Survive the Dead Center campaign.
Spread cheer by helping a free holiday player survive a campaign.
Plays games with free weekend players and helps them survive a campaign.
Play 6 Mutations.
Play 5 full games of Scavenge on The Port.
Play the new Midnight Riders song on a jukebox.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Knock off the heads of 18 infected with the golf club.
Collect 10 items dropped by a Fallen Survivor.
Open 5 foot lockers.
Using the M60, kill 25 infected without letting go of the trigger.
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.
Have Bill sacrifice himself for the team.
Kill a Special Infected with an exploding barrel.
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.
Survive The Last Stand campaign on Expert Realism.
Discover the hidden room in the Last Stand campaign
Kill 53,599 infected. You made sure the dead won't rise anymore!
Earn a silver medal on every official survival map.
Earn a gold medal on every official survival map.
Earn a bronze medal on every official survival map
Survive for 30 minutes on any official survival map.
Earn a gold medal on any official survival map.
Survive for 10 minutes on any official map in Versus Survival.
Destroy 20 gascans as the Spitter.
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.
Instantly kill a Survivor as the Charger.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
As the Hunter, land a 25 damage pounce.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Kill 20 Jockeys with the shovel or pitchfork.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Earn a silver medal on any official survival map.
Earn a bronze medal on any official Survival map.
Destroy a Tank's rock in mid-air.
On the concert finale, survive until the helicopter arrives without leaving the stage
Rescue three Survivors from a single rescue closet.
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.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Survive The Last Stand campaign on any difficulty.
Revive an incapacitated teammate while a Tank is nearby.
Kill a pouncing Hunter with a shotgun.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.