The Grenade Launcher is a primary weapon that made its debut in Left 4 Dead 2. A single-shot weapon, it launches a low velocity explosive shell (grenade) with a blast effect that kills Common Infected and weaker Special Infected in its immediate vicinity. Any Infected who are not killed by the blast are injured and stumbled, excepting Chargers and Tanks who are immune to the stumbling effect.
A break-open design, the Grenade Launcher can only hold one shell at a time and has a long reload time. Since its leaf-type sights are permanently folded down and play no part in its operation, users seeking a distant target must use trial and guesswork to "walk" shells onto the target on account of this weapon's high-recoil looping trajectory. However, because its accuracy is identical to that of the Sniper Rifle when standing still, in theory the only thing required for pinpoint accuracy is the player's range estimation of the arching 40mm HE grenade.
The Grenade Launcher is unique in a number of ways. Primarily, it is not spawned with Tier 1 or Tier 2 weaponry but (like the Chainsaw) is found in peripheral rooms and structures (refer to the Notes section below for an exception). Additionally, it is encountered infrequently and players must not assume that one will reappear in the same place as previously. Finally, it has finite ammo that cannot be resupplied by ammo piles. Once a Grenade Launcher has expended its ammo, it must either be discarded or reloaded with an ammo upgrade (incendiary ammo or explosive ammo).
The Grenade Launcher can inflict heavy friendly fire damage on the user or nearby team members if its explosive projectile strikes a close range target or hard surface.
Highly explosive shells from this weapon are guaranteed to blast infected to pieces within a tight radius, and stagger any infected immediately outside of that radius. It takes a while to reload, so make your shots count. 
- Friendly fire damage on the Grenade Launcher is not too high on lower difficulties, but it becomes a formidable threat on higher difficulties. Great care is thus essential in closely confined spaces and when combat is moving to close quarter conditions; under such circumstances it is often desirable for the operator to switch to a secondary weapon.
- If you are surrounded by a Horde or if a Special Infected is about to grab you, fire at your feet. The surrounding Horde will be vaporized or the Special Infected will probably either stumble or die. On lower difficulties, any self-damage caused will be insignificant. This ploy is not recommended on higher difficulties.
- Self-inflicted friendly fire damage for the Grenade Launcher was increased on the PC version of Left 4 Dead 2 on 9th June 2010 according to player feedback. Friendly fire on teammates from the Grenade Launcher is apparently unchanged.
- If your intended target is several feet away and a Horde of Common Infected are right in front of you, do NOT fire the Grenade Launcher as the splash damage is immense and the Common Infected may overwhelm you if too much health was lost. Try to shove them away or switch to a sidearm/melee weapon.
- Since the grenade is contact fused, it makes excellent sense to aim at hard surfaces in close proximity to the operator's desired target: for example, aiming at a fence that masses of zombies are trying to climb up or the walls of a tight alley choke point (in this regard, refer to the following two Notes for important blast effect data).
- The Grenade Launcher is less effective in wide open spaces as its explosive effect is more diffused and its explosive power is weaker in comparison to a propane tank or pipe bomb.
- If shooting directly at a group of rushing Common Infected, the grenade will hit a few in the front and only stumble the ones behind them. To get the most out of a single grenade on a massed target it is best to shoot from above and aim for the middle of the Horde to kill the most Infected. The projectile's low velocity also requires the operator to lead a moving target.
- The Grenade Launcher is ideal for mopping up clumps of stationary Common Infected in an open area, such as those encountered in the Whispering Oaks' Kiddie Land.
- The Bile bomb works particularly well when used in conjunction with the Grenade Launcher. A Bile bomb creates a large group of Common Infected at a safe distance that can then be obliterated with a barrage of explosive shells.
- The Grenade Launcher stumbles Special Infected that are pinning a teammate at a point of no return or at a distance. Since the pinned player is immune to blast damage, the operator can fire with a clear conscience.
- If a Smoker has just ensnared you, it is easy to hit him with a grenade's blast radius (a direct hit or kill is not required) and save yourself, since the Grenade Launcher always has the same accuracy even when moving. Moreover, when a Smoker has caught a Survivor with his tongue, he cannot move to dodge the grenade.
- While the Grenade Launcher does not do very much damage to a Witch (a direct hit will cause about 550 ~ 850 damage), it does stumble her. This means if a teammate disturbs her, she can be disorientated with a grenade, thereby allowing the offender to escape and make it easier for everyone to kill her. Witches can also be blasted with a grenade from a distance; in this way a team team can take her down very easily.
- With a direct hit, the Grenade Launcher does 1000 damage to a Tank. If used in conjunction with a nearby propane tank or a gas can, the stumbled Tank will be placed at a distinct disadvantage whilst the player reloads.
- In addition to the 1000 damage per shot on a Tank, flames from grenades provided via the use of incendiary ammo with the Grenade Launcher do not wear off on a Tank. A player can use this as a makeshift Molotov with a huge damage bonus.
- In most cases, dual Pistols or the Magnum are better than melee weapons as backup secondary weapons, as they allow the operator to take down individual or small groups of Common Infected from a distance without the need to waste grenades.
- However, sometimes it is better to have a melee weapon as a backup rather than the Pistols for close quarters combat against Hordes.
- The Chainsaw is not recommended as a secondary weapon while using the Grenade Launcher. Both weapons cause high friendly fire damage, have limited ammunition that cannot be replaced, lack precision and long-distance capacities, and have long pauses during use (Grenade Launcher's reload and Chainsaw's draw times). A player is therefore generally better off with a more conventional backup weapon.
- The laser sight confers no benefit to the Grenade Launcher since its shell always follows a slow, looping trajectory.
- When using Incendiary or Explosive Ammo with the Grenade Launcher, the upgrade will give the operator one extra grenade. The Incendiary grenade will set nearby living Infected (of all types) on fire if they would otherwise have been stumbled. Explosive Ammo will give a slightly more potent blast, although it is hard to notice in practice.
- The Grenade Launcher can be used to detonate static explosives such as the propane tank and the gas can. This can make it useful when setting up for a finale, although it makes the Grenade Launcher a hazard in Scavenge mode and in the finales of Dead Center and The Passing.
- Experienced players are inclined to use it as a support weapon and ensure that teammates with other weapons provide cover whilst reloading.
- Extremely powerful
- Can take down Hordes in one or two shots
- Works well with melee weapons
- Can be useful with Incendiary ammo, especially against Special Infected, like the Tank and Charger
- Direct hits can do serious damage to the Tank, often as much as 2,000 damage if done right
- When used properly with the arc, can hit targets from behind cover
- Stumbles Special Infected when they are hit with the shell's explosion
- Can be a very useful support weapon in a Finale static defense scenario, especially where the team has taken up an overlook position
- It is contact fused - meaning that operators can easily injure themselves and teammates with rounds that fall short
- Friendly fire risk―a whole team can be taken down with one misplaced shot
- Very long reload time
- Useless (if not, very dangerous to use) in close quarters situations or confined settings
- Aiming at medium to long ranges is a matter of trial ("walking" shells onto the target) and sheer guesswork
- Ultra-long range "mortaring" is possible - but this is useless since targets beyond direct observation have not yet spawned, with few exceptions
- Takes the place of weapons that could potentially do more damage
- Fast moving Special Infected may be hard to hit
- On Advanced and Expert difficulty, the Grenade Launcher's benefits are heavily out weighed by the downsides; most teams frown on the use of the Grenade Launcher unless in very skilled hands
- Ammo is limited to 30 shells with no possibility of replenishment
- Waste of ammo to kill individual or small groups of infected
- Doesn't stumble Chargers or the Tank
|Kill 15 Infected with a single grenade launcher blast.|
- The Grenade Launcher is modeled after the M79 grenade launcher, which has various nicknames such as "Thumper," "Thump-Gun," "Bloop Tube" and "Blooper" among American soldiers.
- While the Grenade Launcher can kill most Special Infected in one hit, it will only push off a Jockey.
- Also note that the Grenade Launcher not only takes two shots to kill a Charger, but also it does not stumble it either.
- Grenade Launcher grenades will startle the Witch, but drain their health by half. Players who have quick reflexes will be able to take down Witches with little effort by firing on them with the grenade launcher, then quickly running backwards and firing another shot as they begin to chase after them.
- When being killed or hit by the Grenade Launcher, the Special Infected players' ears will ring.
- The grenade's model states that it is a PWN 40MM HE NADE.
- In Single Player/Campaign mode there is only one fixed spawn for Grenade Launcher - on roof of building standing to the right to radio room on rooftop of Mercy Hospital in the ported No Mercy campaign. All other spawn locations for the weapon are randomly chosen by the AI Director.
- The Grenade Launcher seems to have been left behind by the military, although this does not explain why it shows up so often in Swamp Fever, which has a specified lack of any military or CEDA influence. The only explanation is the possibility that they were possessed by collectors as owning grenade launchers, but not their explosive ammunition, is legal with some restrictions in most areas of the south.
- A de-sync glitch occurs when reloading the Grenade Launcher: it finishes faster in third-person view before one can actually fire it again.
- In real life, 40mm grenades do not arm until a minimum safe distance has been reached, measured by the number of rotations of the grenade after discharge - the M79's minimum arming distance is 30 meters (approximately 98 feet). If a target is struck inside this minimum safe distance, the grenade will not detonate. The game does not make this distinction and the M79's shell will explode regardless of distance.
- There is sometimes a glitch which occurs in some finales with Grenade Launchers which spawns an infinite amount of Grenade Launchers (i.e., multiple people can pick up a single Grenade Launcher).
- The Grenade Launcher's model does not have a flashlight.
- Although the Grenade Launcher does not stumble Tanks, the Zombie Survival Guide shows a Tank being stumbled by a Grenade Launcher.
- However, supposed that other weapon's ammunition types are modified through the scripts; such as the entity "sniper_awp"'s ammunition from "AMMO_TYPE_SNIPERRIFLE" to "AMMO_TYPE_GRENADELAUNCHER", it will violently gib Common Infected like a shot from an M60, and stumble any Special Infected supposed that they survive, even Tanks or Witches.
- Oddly, if the Grenade Launcher is fired too close, Survivors will not be stumbled. This also prevents explosive jumping, a common technique in first-person shooter games where one would fire a rocket launcher or similar weapon and jumping at the same time to achieve heights not normally possible by jumping alone.
- In the Developer Commentary on The Bridge, it is revealed that the Grenade Launcher came out of a want to have more explosions in the game.
- The Grenade Launcher seems to be Ellis' signature weapon in official media, as he is seen holding it in the Zombie Survival Guide and some pictures. Despite this, when in the team as a Survivor Bot, Ellis's AI coding precludes him from picking up Grenade Launchers.
- The grenade, strangely, will not explode if fired into the helicopter in the finale of The Parish. It will still detonate if a Survivor or Infected touches the grenade.
- If noclipping on Chapter 2 of Dead Center, venturing into the room where Whitaker is holding out will reveal that he is holding an M79 grenade launcher to blow up the fuel tanker even though its missile is depicted as firing like a rocket-propelled grenade.
- As opposed in having a fixed arc and the projectile behavior fixed while the gravity also acts upon it, the grenade's trajectory is automatically adjusted to specifically hit where the cross-hair is aiming at. It may be possible if Survivors automatically account for the distance and adjust the angle of the grenade launcher accordingly, but as seen the view model remains static. When fired vertically, the grenades shot continuously fly into the sky instead of later coming down, even when the projectile speed is lowered.
- There's a trick to launch a survivor high in the air. It's all about the precise timing of the jump and precision of firing the launcher. Have one survivor stand at a spot where there's elevation. While the grenade launcher user stand below the survivor. Have the victim jump constantly, make sure to crouch after each jump. While the victim is in the air, have the grenade launcher user fire at their feet. If done correctly, the victim will be launched high in the air, sometimes accessing unreachable areas. This is very useful in certain survival maps in which the team can get the highest record easily. It's possible to do this with a Bile Bomb as well.
- It is possible to get Incendiary or Explosive ammo for the Grenade Launcher, although only one round will have the Incendiary or the Explosive effect (Because the Grenade Launcher has only 1 round loaded).
- Zoey does not use the correct animation while holding the Grenade Launcher, and poses as if she is holding a Hunting Rifle.
- Strangely, Bot Survivors will never pick up the Grenade Launcher in normal gameplay. This also applies to the M60 and all melee weapons.
- Much of the time, the environment is not affected at all by grenade launcher blasts. Cars and trucks do not explode when shot with a grenade launcher. Structures made of wood or other weak materials are not destroyed or set on fire by grenade launcher blasts. Glass windows or bottles (e.g. Molotovs and Bile Bombs) that aren't in the immediate blast radius of the grenades are not broken by the pressure wave from the explosion, and even Molotovs and Bile Bombs that are in the blast radius are not broken by the explosion.
- Swamp Fever Grenade Launcher Gameplay
- PAX Dark Carnival Grenade Launcher Gameplay
- Whitaker holding an M79 grenade launcher on Chapter 2 of Dead Center
- Grenade launcher in action
|Left 4 Dead|
|Tier 1||Pump Shotgun / Submachine Gun|
|Tier 2||Assault Rifle / Auto Shotgun / Hunting Rifle|