You can also 'overcharge' the weapon by holding down the fire button. The damage the projectile does to everything along its path is small compared to the destruction at the point of impact (aim away from face). Use it to kill a room of demons without breaking a sweat. This is the biggest gun in the Marine arsenal.Get your first taste of rocket power in the Toxic Disposal Maintenance area near the end of the Monorail Skybridge. Rockets are also your primary boss-killer since they reload fairly fast (better than the shotgun and does more damage), so save them for boss fights. The idea situation is a tightly grouped bunch of suckers in a narrow hallway, but that seldom happens in the game. You also only have five shots, so wasting them on single enemies coming at you from all around is not a good idea. When you want a demon absolutely, positively dead in less time to say it, use the rocket launcher. This is your one hit kill weapon for the majority of the game.Get a plasma rifle at Alpha Lab Sector 4's EFR Pressure Station and in the EnPro Plant's Maintenance Area 1. Strangely, the plasam bullets can be blocked by fences and environmental obstacles. Plasma ammo is fairly uncommon when compared to the ammo for the assault rifle, so save the plasma rifle for Imps and such (not zombies) in wide open spaces. The shots actually travel slower (since you can see them) but they are fairly fast. The plasma gun is a suped-up version of the assault rifle.Grenades are found in various stowage lockers, so keep some handy for tough situations. Holding the fire button longer throws the grenade further, so don't tap fire, or you may wind up with a grenade dropped at your feet. Since they bounce off walls, you can toss them around a corner while retreating from a demon and blow the enemy right up. Basic explosive charges that detonate on impact with objects and enemies.You can pick up this baby in select places - the locker in the Administration's North Hall and later on in Alpha Lab Sector 3's Heavy Water Runoff. It does more damage than the assault rifle, but takes time to wind up to fire, so it's not great if a demon pops up in front of you and starts gnawing your balls. A highspeed rapid fire support weapon like 'Old Painless' from Predator (or Arnold's GE from T2).Many of the Z-Sec zombies carry this weapon, so it will not be in short supply if yoru weapons get taken away. If you're in doubt and have the ammo, you can use this weapon on the zombies and weak enemies in the game. This is best used for small enemies or hordes of small enemies, or long range sniping. Rapid fire weapon with good accuracy, unlike the weapon in Halo.Shotguns are fairly common, and some Z-Sec zombies carry them (don't get close). Switch to another weapon to keep fighting.

You're also only good for eight shots, so once the gun runs dry, you will not be doing much except watching shells reload.

Doom 3 plasma rifle