Chapter 3 - Marine Strategies

Smartgun
Faster than the pulse rifle and sporting the ability to carry more in a single clip, the smartgun is a weapon of choice in later levels of the Marine campaign. But, that's not even its best feature; the smartgun can be set to both track and free mode. When used in tracking mode, your crosshair will follow any enemy that approaches from the front. While it's sometimes difficult to take down fast-moving Aliens, it at least lets you know that an Alien is approaching from the front. Against the surprise-happy Aliens, getting that knowledge of an oncoming attack can mean the difference between life and death.

After you've got a sight on the incoming Alien, you probably should switch the smartgun back to free mode, which means wherever you point the weapon, that's where it'll shoot. Dishing out a comparable amount of damage to the pulse rifle, the smartgun is best used against the standard Alien foe.

Flame thrower
The flame thrower is somewhat of a mixed bag. A potent close-range weapon, the flame thrower has no problem dishing out pain in close quarters, but the biggest problem is that you really don't want your enemies that close to you! If you ignite a standard Alien enemy, he'll remain alive for several seconds, eventually exploding into a hump of acidic goo. But while he's still alive, he'll make every effort to take you out
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If you have nothing else available, the flame thrower will certainly work. But, after igniting the enemy, you best get away quickly and wait out the explosion process. Perhaps its best use is against Alien Facehuggers. These small, fast scurrying little spider-like beasts give pulse rifles and smartguns fits. But, they aren't much of a match against a few quick bursts of the flame thrower. Use your image intensifier to spot them, then pump out some napalm from the flame thrower. After a few moments of scurrying around, the Facehugger blows up.

SADAR
The mother of all weaponry, the SADAR rocket launcher packs the biggest punch in the Marine's arsenal. A powerful weapon in both the single-player and multiplayer games, seek out the SADAR as soon as you can (in the single-player game, it only appears in a few spots in Director's Cut mode). Though it's slow to reload, the sheer amount of damage you can do makes it an ample trade-off.

Don't waste ammunition against standard Aliens or simple Facehuggers; save the rockets for the tough guys, like the Predator or the Praetorian. Like the pulse rifle's secondary grenade function, don't stand too close to the blast or you'll find yourself exploding with your enemy. Finally, aim for the feet or the ground just around the enemy you're firing at. It's quite difficult to get an accurate shot on the head or the chest; if you aim at the feet or the ground, you'll either hit directly or cause blast radius damage to the foe.