Mairnes
Marine Weapons
The marine has a high power arsenal. Unlike the predator, who gets almost all his weapons at the beginnning,and the alien whose defense is its deadly claws and tail, the marine must find its weapons to succeed. The marine has the widest range of weapons. From the flamethrower to the deadly minigun he is not as specialized as either the predator or aliens.
Pulse Rifle
The pulse rifle is the marine's default weapon. This is essencialy a machine gun. It also comes with a built in grenade launcher. Each clip for the pulse rifle holds 99 bullets. 99 may seem like alot but can run out real fast. If you know you're going to be facing a lot of enimies you may want to empty out the last of your bullets in that clip. The pulse rifle is actually a very good weapon for taking out predaliens. Just aim for the head and after a few hits the head will pop off(this is actually better than the grenade launcher for taking out predaliens). The pulse rifle has its own built in grenade launcher, not to be confused with the real grenade launcher. The pulse rifle's has a relatively small blast raidus but is still useful if you want to take out groups of enimies.
Pulse Rifle Against Aliens
You'll probably use the pulse rifle a lot against aliens. They are your most common foes. Try to hit them in the head. This will give a lot less acid spray back. Use the pulse rifle at medium range for best effect. The built in grenade launcher is good for clearing out groups of aliens. However, it is not best against single aliens because you have to be very precise in your aiming. Overall, the pulse rifle is very effective against aliens and is probably what you will use most against them.
Pulse Rifle Against Predators
The pulse rifle is not what you want to use on the predator because of their superior strength. If you are forced to, fire both grenades and bullets into them to wipe them out. Chances are that you will not kill them very eaily with the pulse rifle. If it looks like the pred will fire than get out of there. You'll be dead if you don't. Pulse rifle is definenently not the best weapon against predators.
Pulse Rifle against Marines
The pulse rifle works well against the marine. The marines are almost as weak as the alien and will be killed very quickly under sustained fire with the pulse rifle. One direct grenade hit will wipe them out. In fact it doesn't really matter which weapon you use on the marine because they aren't fast and they're pretty weak.
Smartgun
The smartgun is a faster better pulse rifle. It also holds a lot more ammo so you don't have to worry about running out. The smartgun has autoaiming and is good against distant enimies. The secondary fire for this weapon switches on and off the auto-aiming. Because this is much like the pulse rifle those strategies are usefull for it.
Smartgun Against Aliens
The smartgun works about as good as the pulse rifle on aliens. If they are far away you'll probably get a good hit in on them and they won't have time to get close enough to attack you. The game guide suggests you turn off the auto-aiming and I do that sometimes. However, I think that the auto-aiming is still usefull againt aliens, especially distant ones.
Smartgun Against Predators
Its better to use the smartgun agaist preds. than it is to use the pulse rifle. This is because the smartgun is both more powerful and can carry more ammo. You will not have to worry about running out of ammo if you have a full clip. The smartgun also deals more damage and will kill the predator faster than the pulse rifle even though it doesn't have a built in grenade launcher. A little bit better of a choice but still not the best against predators.
Smartgun against Marines
The smartgun is a good feature to use against marines. It will kill them in a few seconds of sustained fire. You will not have to use the smartgun or any weapon against marines in single player. In multiplayer the smartguns auto aiming is good against marines because they are so slow. However, don't choose this as your only weapon or you'll be sorry.
Flamethrower
The flamethrower is a relatively specialized weapon. It goes throw ammo rather quickly so be careful to use it. DO NOT use the flamethrower while walking forward. You'll instantly catch on fire. The only way for you to put out the fire is to get a medkit and chances are that you will not be close enough to administer your self one. The flamethrower is a great weapon to use to cover your escape. Walk backwards while shooting the flamethrower and any enemy that follows will burst into flame. In multi-player this is especially useful.
Flamethrower against Aliens
Unfortunatly the flamethrower does not cause an instant death. An alien that is on fire will probably try to take you with it as it burns. The animal will eventually die however,so this is a great hit and run weapon against aliens. In order for the alien to put out the fire they will have to run around very quickly for a short amount of time. Switch weapons and take them out while they're doing this. The flamethrower is also useful against enemy facehuggers. The second they start on fire they will not be able to hurt you. When you think there are facehuggers around, shoot the ground with flame and they will be ignigted.
Flamethrower against Predators
It will take an extremely long time for the flamethrower to kill the predator. For the predator to extinguish flames it must use the medcomp. Do what you did with the alien and change weapons to something like the sadar or mini-gun. Don't use any of the first three weapons on the predator if you have the choice. They will not do enough damage to kill him in that limited amount of time before he uses one of his high power weapons.
Flamethrower Against Marine
If you're going to use the flamethrower against anyone, use it against the marine. The marine must locate a medkit to heal itself. The chance of them doing this before they die is remote. They will probably try to kill you and can do so quickly with their arsonal. Just get them on fire and hope they don't find a medkit. Run away. Don't stick around to watch them burn or you'll end up with a bullet in your brain.
Sadar
The sadar is the marine's rocket launcher. Its blast radius is unsurpassed and is one of thier most powerful weapons. Fire the weapon at the enimies feet and not their general direction. This way, even if you miss, you'll deal out heavy splash damage. Use the sadar against anyone you meet in multiplayer, you need the points. In single player, use it against especially powerful enimies.
Sadar Against Aliens
No matter how you use it, the sadar is deadly to aliens. If they are even hit by just a little of the blast they will die. The sadar also will spray their acid blood every where. Use the sadar at great distance against aliens. Otherwise you will probably get a lot of damage from acid blood. If you see a lot of aliens and have the sadar you can use it on them. Otherwise wait for stronger enimies.
Sadar Against Predator
By this time you're probably wandering what a good weapon is to use against the predator. The pulse rifle, smartgun, and flamethrower are not good. At least not against predators. The last three and most powerful weapons are all good bets against predators. The sadar will take out the predator quickly enough. You can run in, fire and run out without getting injured. Hit and run tactics, my favorite:)
Sadar Against Marines
The sadar will incinerate a marine with one hit. Great use. Great effect. That's about it
Grenade Launcher
The grenade launcher has a wide range of ammo. It has normal grenades, fragment grenades, and proximity grenades. The normal grenades will explode after three seconds. They are good for lobbing around corners and off ledges to get an unsuspecting victim or two. Fragment grenades are just like normal grenades except that they will shoot fragments of rock all over the place. The damage of these fragments varies depending on whether or not the hit is direct. Proximity grenades will stick to any surface and detonate when a life form gets in their radius or after 20 seconds. Use them to cover your escape or to surround yourself for a nice surprise. Any of the grenades will detonate if they get a direct hit. Grenades can be dangerous if used wrong. Be careful to remember where you placed proximity grenades.
Grenade Launcher Against Aliens
The aliens are fast. Keep this in mind when trying to use the grenade launcher against aliens. Because there is a three second delay, the alien will probably get to you before the grenade goes off. Lob the grenades around corners if you think an alien is over there. The aliens might set off the proxies. and get out of the way before it detonates. If you are in close corridors, shoot proxies behind you so that any alien coming will be blown up.
Grenade Launcher Against Predators
If I had the choice between the grenade launcher and the sadar to use against predator, I would use the sadar. The grenade launcher is just not as powerful as the sadar. Take my advise, out ot the last three weapons the grenade launcher is the least powerful. Use the same strategies that you used against the aliens. The pred. is a bit slower and will be an easier target to hit with any type of grenade.
Grenade Launcher Against Marines
The grenade launcher is my favorite weapon to use against marines because they are both slow and weak. They won't be able to run past proxies and live like the alien, and they won't be able to take as many hits as the predator. You have a much better chance of getting a direct hit and therefore getting a direct kill. If you choose to have a game of just marines, use the grenade launcher a lot. It'll put you on top.
Mini-gun
The mini-gun is the ultimate weapon. Nothing can withstand its wrath and once you get it you are practically invincible. You will barely ever find the mini-gun in the single player game and when you do save it for really strong enimies. There are barely any problems with this ultimate weapon. The big one is its jarring kickback. You'll also use up ammo really quickly but you won't be using it for more than a few seconds anyway. Everything you see will be as good as dead.
Mini-gun Against Aliens
The alien is dead if hit by the bullets of the mini-gun. Don't use it unless forced to in the single player game. Don't waste it. In multiplayer, shoot once and boom the alien'll die. That's just about it.
Mini-gun Against Predators
The mini-gun is the best weapon to use against the predator in single player. Don't worry, this is a good idea even if you only find it one or two time. The predator is what you should save the mini-gun for.
Mini-gun Against Marine
The marine will die just as quickly as the alien when hit by the mini-gun. Blast on!!!!
Vision Modes
Normal Vision
Normal vision is, well, normal. It is light dependent. If there isn't light you can't see(duh). In normal vision there is also a motion detector, more on that later. Aliens will often jump out of the darkness when you least expect it. Always be on the look out for enimies. You'll probably use normal vision most of the time except for areas of extreme darkness. You get the advantage of the motion detector and won't get the white out effect when you shoot your weapon or throw a flare.
The marine has an unlimited number of flares. However, they can only throw up to four at one time. The flares light up the surrounding areas for a few moments. Use these when you won't be in the dark for very long. Don't ever even think of using flares when you have your image intensifier on. This will create a whiteout effect. Here is one usefull strategy I sometimes use in multiplayer. If there are lots of other marines around, blow out all of the lights. This is not a suicide plan so don't ask. The other marines will turn on their image intensifier. You won't. They will not have their motion detector so they will have to rely on sight. Since you won't be turning on the image intensifier you will have to rely soley on your motion detector because of the darkness. When you think you are near a guy, throw some flares. Hopefully they'll see you first and shoot. That will light up the screen and you will know where they are. The second you throw the flares they will be blinded and will not be able to shoot with accuracy. The first thing that they would want to do is turn off their image intensifier and that will give you just enough to gun them down. This strategy also works against aliens when they have their night vision on, but when I play as an alien I usually don't turn on night vision unless I really have to, I just look for the aura. This plan can backfire if you're not good at using the motion detector or the other player has really good aim or a sadar or grenade launcher. But hey nobody's perfect.:)Flares
Image Intensifier
The image intensifier creates a grainy green image that is best for total darkness. The image intensifier is what makes the flare trick above work. A lot of weapons will cause whiteout on the screen if used with the image intensifier. Never use the I.I. when in the light. if you want more light just use flares. In multiplayer a lot of tricks can be pulled off if the person has their image intensifier on. Does this mean that you should never use your image intensifier?No, it can help find aliens in dark rooms and tunnels. In fact, some people use the image intensifier all the time because the aliens won't be able to sneak up on you all the time.
Falling Damage
The marine gets the most falling damage out of any time. They will get injured very easily by falling. Do not play the marine like you would other fps characters. You can not jump off a ledge to investigate something. Instead, take the stairs or find an elevator. You can't be reckless playing as the marine.