Anti-armor, anti-personnel high explosives.
Launchers are high-powered explosive weapons, primarily intended for crushing enemy scorestreaks and emplaced equipment.
Launchers usually aren’t a good choice for general-purpose loadouts, except for objective builds where you intend to use the P-LAW or Howitzer for clearing objective points.
Spartan SA3
Lock-on launcher. Primarily anti-air with an optical smart lock, but can be dumb fired.
The Spartan is the main anti-air launcher in the game, and should be your go-to weapon for knocking UAV support out of the sky, or destroying the Warden, AP-3X, or R-C8. It is also quite useful for destroying the Shock Sentry if you’re running Blind Eye or using Smoke Grenades.
It is possible to destroy an enemy AUAV, but you really need two players with Spartans both firing on it the instant it comes online, which can be tough to coordinate unless you’re in an organized group. It is possible to destroy one solo, but you need to be fast.
The Spartan can also be dumb fired, which gives it an extra role for tackling enemies in clustered groups, narrow spaces, or camping in windows.
P-LAW
Charged Energy launcher. Deploys volatile plasma charges that explode for extreme splash damage.
The P-LAW is a direct-fire launcher, good for taking out enemies or equipment if you have a clear line of sight.
Unlike the Spartan, you can’t get a lock, so it’s a poor choice for anti-air, and because it has a charge time, it’s not a good choice for combat out in the open.
However, if you pre-charge the P-LAW and poke around hard cover to fire the blast, you can inflict some serious damage without exposing yourself to much risk.
Howitzer
Grenade launcher. Launches quick, deadly projectiles that explode on impact.
The Howitzer is your second straight explosive option, and unlike the P-LAW, it fires its projectiles in an arc, which allows you to fire them over cover, a trick the P-LAW isn’t quite as adept at.
The Howitzer works quite well for lobbing explosives into objective areas and tight rooms. It takes a bit of practice to learn the angle you need to fire shots, but it’s a fairly easy skill to master, and you can practice in a private lobby with some friends if you want to figure out where you can “mortar” shots across the map from behind cover to hit key objectives.