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 name of the 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. While Lasguns are never realistically depicted, having all the properties a bullet-thrower would, a Lascannon is depicted more like a particle beam cannon than anything that would scientifically be considered a Laser; the overall implication is that lascannons use laser-induced fusion to turn hydrogen into a fast-moving, very hot stream of helium plasma, granting them their name.
Then again, it is based on Dark Age of Technology knowledge, so it may well somehow accelerate photons and the Mechanicus is simply too afraid to mess with its design to discover that making the beam narrower would result in an increase in effectiveness. That, or they just want to cover as much of the target as possible so they give it a big beam because they lost so much knowledge that they don't know it will weaken the strike. Or perhaps they think it has enough penetration power and want to focus on making really big crispy/molten holes in things or blasting them apart like some kind Godly SMITE CANNON.
In all seriousness, a laser causes what it touches to explosively flash into plasma if the laser is strong enough. A lasgun is strong enough to blow a grown man nearly in half and at least damage pretty much anything (which is why numbers matter against armored targets, usually armor wouldn’t work that way vs other types of weapons). Due to working on a sub-atomic level. So, a lascannon could do the same with far greater effectiveness. The beam doesn’t need to penetrate to at least crumple a large section of armor or outright destroy it for infantry to slaughter the gooey innards.
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.
The Lascannon is primarily designed for anti-vehicle combat, but regularly sees use against Tyranid monstrous creatures and the errant target on the battlefield that a commander needs to remove right the fuck now, such as a commander sans retinue from a good distance. While it's not the best weapon in the 41st millennium for the job (the Tau Railgun with its plasma-wrapped slug ammunition-firing dipshit range/punch/AP is slightly stronger, as are some ordnance weapons such as those used by The Imperial Guard, while the Necron Pylon's weapon has SD AP 1 and can fire three times in one turn. The Gauss Cannon is ever so slightly better and some Titan weapons make the Lascannon look like a piece of junk..), the Lascannon is undeniably the most cost-effective at what it does - most of these other weapons are a lot more expensive, and the Lascannon does their job almost as well for ten fuckloads cheaper. However, the lascannon is substantially more expensive than other solutions for a wide variety of targets; for example, an Imperial Guard heavy weapons team will do more expected wounds/hp per point to any Toughness (since the highest value in the game is 9, and there are no Toughness 4 models with enough wounds for Instant Kill to make up the difference) and any AV below 14, ignoring saves.
It's hard to go wrong with the Lascannon. Ask for it by name.
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 settings would dent the frontal armor but also wreck the side and rear armor of almost anything (it's closest 40k relative would likely be like if there was a Taurox version of the Vanquisher Cannon) but thanks to it's High AP and strength the Lascannon is one of the few weapons that can say screw that to even super heavy's like Baneblades and Titans if you get enough of them together. 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.
|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
|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