It is very important to know what weapons to use on different enemies.This guide will help you out.

Heavy weapon dude=shotgun
mancubus=supershotgun
arachatron=rocket launcher
reavant=supershotgun
arch-vile=plazma rifle
hell knight=supershotgun
Final deamon=rocket launcher
Pain elemantal=plazma gun

I know,I know!I didn't include every monster!The only monsters that I included are ones that have their first appearance on doom 2.On the doom 1 forum there are all the other ones.

everything:BFG9000

Not exactly the best one to use on everything,because that would just be a waste of cells.

uhh.. idkfa would solve that.

no just joking, i use shotgun for most of the enemies because its very efficient and u get it it in large quantities in the game.. since im a expect at the game after playing all those years i try go through the game with just the super shotgun weapon... just when it comes to the main 3 bad guys u need rocket power or better yet a huge mother f***in gun!!

damb those arch viles are the worse sons of bitches on planet earth!

These are my tips,

Pinky's (Demons) Whenever possible, and it's only Pinkys coming at ya, back into a corner make sure you can't be attacked from the sides, and break out the trusty chainsaw. These guy's love it, and just will keep coming back for it. a good example of this is the level "Trick's and Trap's" Theres tons's of Pinky's on this level, And you save a heap of ammo.

I find the Super-Shotgun the best allrounder, this will take out most enemys, and weaken some of the harder ones, so you'll just have to clean up with a more powerfull gun.
If your skilled enough at using strafe, you can take out Spiders, with 3-4 good hits.

Another good tip is the use of the Chaingun, For the Demons that throw fire balls and the lost souls, Pinning them down with the Chaingun can stop them from firing at you, or stop a Lost Soul in it's tracks....

Long live DooM.

Yeah, when a lost soul is attacking, hit it with anything, that will stop it from moving. then, if you save it right away, it will stop moving forever.

What game did the arch vile appear in because I have never seen it and I have all the original games (1 2 and final) I have seen screen shots of it in doom 1 but i can't find it!

There are no arch viles in doom 1.

The archvile's first apperance in DOOM2 is in MAP11: circle of death. I think it is right by the blue key.

I just use the chainsaw against the pinkeys.

Why did they put it right at the beginning of the game??

I use a chainsaw on Archviles and they cant hit me, it also saves the ammo for your more powerful weapons.

the shotgun is best for the lost souls as for pain elementals run away from them it's bad if u kill them and it's bad if u don't use the chaingun on the revenants and cacodemons the plasma gun on arch viles and rocket launcher on hell knights

all i have to say