Unlike the Lasgun, the Lascannon is a flashlight that may be considered badass. Lascannons go FREEEM! or FOOSH! There is an ongoing debate on the pronunciation of "lascannon." As lasers are LAY-ZERZ, some players know the lascannon as the lays-cannon. YOU WISH IT COULD SHOOT POTATO CHIPS! It can't be called a debate when the powers-that-be already stated that it is pronounced like laser but with the "er" removed, but nobody at GW seems to actually stand by this ruling as several official videos, interviews, and audiobooks pronounce it the other way.

In all seriousness, a laser causes what it touches to explosively flash into plasma if the laser is strong enough. A normal lasgun is strong enough to blow an unarmored human nearly in half and, due to the way lasers work, can damage pretty much anything eventually. So, a lascannon does the same with far greater effectiveness. The lascannon beam doesn’t necessarily need to penetrate its target either. In many cases, the explosive damage caused by the hit itself will be enough to critically damage a target. The lascannon is, like the lasgun, a laser and does not "cut" or "bore" into a tank so much as make part of the vehicle explode with the force of a bomb. This thing will fuck your shit up and fuck it hard.

The lascannon is often placed as a phallic symbol on many Imperial Guard Leman Russes, because they thought the battle cannon was not enough. Spess Mahreens often use them in their Devastator Squads, because they are simply better than their Guardsmen counterparts, and want to make sure that's clear. But like their Guard counterparts, they like to stick them on all the tanks they have, because they are Spess Mahreens, and they're cool like that. Being an energy weapon, the Lascannon shares many drawbacks of similar weapons fielded by the Imperials in that it's not terribly energy-efficient, but it's hard to find a better anti-tank weapon or tool for reliably hurting lone high-threat units on the battlefield. Seeing as it is Strength 9, AP2, and Heavy 1, it really has no other use, save for what is ultimately sniping, only that vehicles and monstrous creatures are also on the list of targets, while squadded commanders are not.

Lascannons use single-charge power packs similar to las-gun power packs, but the size of a car battery and good for one shot. This means they have to be reloaded after each shot, like a missile launcher. Tanks with lascannons use a bank of these packs to help distribute the charge and recharge spent packs between volleys. They are most visible in the Predator tank and Sentinel walker. Theoretically, a Space Marine could hook up a scaled-up hellgun to his miniature nuclear reactor backpack and just let loose with some sort of hellcannon, but that would mean thinking and thinking is heresy.

Chaos Space Marine Havocs are known for cramming Bayonets on the things. Because everything's better when you make it moar choppy.

The Lascannon is primarily designed for anti-vehicle combat, but it also sees use against monstrous creatures and the errant battlefield target that a commander needs to remove right the fuck now, such as isolated enemy characters. While it's not by any means the most powerful anti-armour weapon on the tabletop, the lascannon is still quite effective, and in the case of Imperial armies, it is available in quantity. Just bear in mind that when forced to operate outside its preferred role of burning down tough, high-priority targets, the lascannon is far less efficient.

If the Lasgun hits with the power of over double that of an AK47, then a Lascannon would most likely hit with the force of a 120mm APFSDS round, which by WH40K standards is sufficient to threaten nearly any armored target in the game, even super heavies like Baneblades and Titans if you get enough of them together.

It's hard to go wrong with the Lascannon. Ask for it by name.

Weapons of the Imperium of Man
Sidearms: Arc Pistol - Autopistol - Bolt Pistol - Flechette Blaster - Gamma Pistol - Grapnel Launcher
Grav-pistol - Hand Flamer - Handbow - Helfrost Pistol - Hellpistol - Inferno Pistol - Kinetic Destroyer
Laspistol - Needle Pistol - Phosphor Blast Pistol - Phosphor Serpenta - Plasma Pistol
Radium Pistol - Reductor Pistol - Stub Pistol - Volkite Serpenta - Web Pistol - Neural Shredder
Basic Weapons: Arc Rifle - Autogun - Bolter - Bow - Crossbow - Hellgun - Lasgun
Radium Carbine - Shotgun - Storm Bolter - Stubber - Webber
Special Weapons: Combi-weapon - Conversion Beamer - Flamer - Grav-gun - Grenade Launcher
Long-Las - Meltagun - Needle Sniper Rifle - Plasma Caliver - Plasma Gun - Adrathic Destructor
Radium Jezzail - Sniper Rifle - Transuranic Arquebus - Volkite Charger - Photon Thruster
Galvanic Caster - Galvanic Rifle - Psilencer - Hotshot Volley Gun
Heavy Weapons: Autocannon - Grav-cannon - Harpoon Gun - Heavy Arc Rifle - Heavy Bolter - Heavy Flamer
Heavy Stubber - Heavy Webber - Helfrost Cannon - Lascannon - Missile Launcher
Mortar - Multi-Melta - Multi-laser - Phosphor Blaster - Plasma Cannon - Volkite Caliver
Volkite Culverin - Seismic Cannon - Darkfire Cannon
Battle Cannon - Conqueror Cannon - Demolisher Cannon - Heavy Phosphor Blaster
Helfrost Destructor - Hydra Autocannon - Magma Cannon - Nova Cannon - Pulsar-Fusil
Punisher Gatling Cannon - Vanquisher Cannon - Volcano Cannon - Volkite Carronade
Heavy Seismic Cannon - Laud Hailer - Adrathic Devastator - Gatling Psilencer - Ferrumite Cannon
Ordnance: Accelerator Cannon - Baneblade Cannon - Colossus Siege Mortar - Deathstrike Missile
Dreadhammer Cannon - Earthshaker Cannon - Griffon Heavy Mortar - Belleros Energy Cannon
Hellhammer Cannon - Manticore Missile - Medusa Siege Cannon - Quake Cannon
Stormshard Mortar - Stormsword Siege Cannon - Tremor Cannon
Apocalypse Missile Launcher - Doomstrike Missile Launcher - Gatling Blaster
Hellstorm Cannon - Inferno Gun - Laser Blaster - Macro Cannon - Melta Cannon
Plasma Annihilator - Plasma Blastgun - Plasma Destructor - Plasma Obliterator
Turbo-Laser Destructor - Vengeance Cannon - Vortex Missile - Vulcan Mega-Bolter
Sonic Destructor - Sonic Disruptor - Thundercoil Harpoon - Arachnus Magna-Blaze Cannon
Melee Weapons Chainweapons - C'tan Phase Weapons - Force Weapons - Power Weapons
Transonic Weapons - Basic Close Combat Weapons - Miscellaneous Weapons
Grenades & Explosives Frag Grenade - Krak Grenade - Melta Bomb - Smoke Grenade - Blind Grenade - Shock Grenade
Vortex Grenade - Stasis Bomb - Psyk-Out Grenade - Rad Grenade - Demolition Charge - Mindscrambler Grenade
Weapons of the Genestealer Cults
Sidearms: Autopistol - Bolt Pistol - Hand Flamer - Laspistol
Needle Pistol - Web Pistol - Liberator Autostub
Basic Weapons: Autogun - Lasgun - Shotgun - Webber - Storm Bolter
Special Weapons: Flamer - Grenade Launcher - Sniper Rifle - Mining Laser
Silencer Sniper Rifle - Proclamaitor Hailer - Scrambler Array
Heavy Weapons: Autocannon - Heavy Bolter - Heavy Flamer - Heavy Stubber
Missile Launcher - Mortar - Multi-laser - Seismic Cannon
Heavy Mining Laser - Atalan Incinerator - Multi-Melta
Plasma Cannon - Lascannon
Battle Cannon - Clearance Incinerator - Eradicator Nova Cannon
Heavy Seismic Cannon - Hunter-Killer Missile
Vanquisher Cannon
Melee Weapons Chain Weapon - Power Weapon - Tyranid Close Combat Weapons
Heavy Rock Drill - Heavy Rock Cutter - Heavy Rock Saw
Miscellaneous Weapons - Basic Close Combat Weapons
Grenades & Explosives Frag Grenade - Krak Grenade - Blasting Charges
Weapons of the Forces of Chaos
Sidearms: Autopistol - Bolt Pistol - Stub Pistol - Warpflame Pistol
Injector Pistol - Xyclos Needler - Plasma Pistol - Inferno Bolt Pistol
Basic Weapons: Autogun - Bolter - Fatecaster Greatbow - Lasgun
Shotgun - Stubber - Inferno Bolter - Sonic Blaster
Special Weapons: Flamer - Conversion Beamer - Meltagun - Plasma Gun - Doom Siren
Sniper Rifle - Warpflamer - Bile Spewer - Combi-Bolter - Sonic Shrieker
Heavy Weapons: Æther-Fire Cannon - Autocannon - Heavy Bolter - Heavy Flamer - Heavy Stubber
Lascannon - Mortar - Havoc Launcher - Plasma Cannon - Blastmaster
Reaper Autocannon - Soulreaper Cannon - Plague Sprayer - Plague Spewer
Blight Launcher - Heavy Warpflamer - Heavy Conversion Beamer - Hellfyre Missile Rack
Daemon Weapons: Kai Gun - Fleshmetal Guns - Harvester Cannon - Mawcannon - Butcher Cannon
Soul Burner Petard - Storm Laser - Skull Hurler - Cauldron of Blood Cannon
Hades Gatling Gun - Ichor Cannon - Gorestorm Cannon - Daemongore Cannon
Hellmaw Cannon - Scorpion Cannon - Tormentor Cannon - Plaguespitter
Heavy Blight Launcher - Plagueburst Mortar - Rot Cannon - Beam of Power
Warpfire Flame Cannon - Ectoplasma Cannon - Skull Cannon - Bolts of Change
Skullreaper Cannon - Skullshredder Cannon - Doomfire Cannon - Impaler
Kytan Gatling Cannon - Balemaw Cannon - Plague Catapult - Excruciator Cannon
Magma Cutter - Pandemic Staff - Mirror of Absorption
Battle Cannon - Dirge Caster - Single-Barrelled Turbo-Laser Destructor
Hurricane Bolter - Demolisher Cannon - Accelerator Autocannon
Punisher Gatling Cannon
Ordnance: Apocalypse Missile Launcher - Doomstrike Missile Launcher
Gatling Blaster - Hellstorm Cannon - Inferno Gun - Laser Blaster - Macro Cannon
Melta Cannon - Plasma Annihilator - Plasma Blastgun - Plasma Destructor
Plasma Obliterator - Vulcan Mega-Bolter - Double-Barrelled Turbo-Laser Destructor
Volcano Cannon - Pus Cannon - Vengeance Cannon
Melee Weapons Chainweapons - Power Weapons - Daemonic Close Combat Weapons - Arc Weapons
Tzaangor Blade Weapons - Basic Close Combat Weapons - Force Weapons
Grenades & Explosives Frag Grenade - Blight Grenade - Krak Grenade - Melta Bomb