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