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