If you get trapped by a barnacle (those things with the long, sticky strings hanging down), quickly pull out your crowbar and attack the creature to kill it in one hit. Don't try this if the barnacle is on a high ceiling, though, as you'll take quite a bit of damage from the fall. You can also equip your crowbar and allow yourself to get dragged up to kill the barnacle and save some ammunition.

$16,000 impulse101
Adjust gravity sv_gravity <-999 - 999999>
Arctic sniper rifle give spaceweapon_awp
Auto-aim with sniper rifle sv_aim
Auto-reload disabled -reload
Auto-reload enabled +reload
Change crosshair color adjust crosshair
Change skins skin
Disable the crosshair to enlarge when shooting crosshair <1-5>
Faster backwards motion cl_backspeed 999
Faster forward motion cl_forwardspeed 999
Faster side motion cl_sidespeed 999
Get indicated item give
Hyper auto-aim disabled sv_clienttrace 0000
Hyper auto-aim enabled sv_clienttrace 9999
Level select changelevel
Reveal how much time is left on the map timeleft
See and fire through walls and objects, default is 3600 gl_zmax<0-9999>
See things brightly without flashlight lambert -1.0001
Set freeze period at the start of rounds. Set to 0 to disable, default is 6(For use on server machine only) mp_freezetime
Set maximum length in minutes a round can last, default is 5(For use on server machine only) mp_roundtime <3-15>
Set minutes between map rotations, default is 0(For use on server machine only) mp_timelimit
SetC4 timer mp_c4timer <1-100>
Toggle auto-help hint messages, default is 1 ah <0 or 1>
Toggle crosshairs in observer mode, default is 1 cl_observercrosshair <0 or 1>
Toggle flashlight use, default is 1(For use on server machine only) mp_flashlight <0 or 1>
Toggle footsteps, default is 1(For use on server machine only) mp_footsteps <0 or 1>
Toggle friendly fire(For use on server machine only) mp_friendlyfire <0 or 1>
Toggle graph net_graph <0 or 1>
Toggle map briefings after new levels load, default is 1 dm <0 or 1>
Toggle to see ghosts in observer mode, default is 0 ghosts <0 or 1>
Unbind key command unbind
View other players' frags cl_hidefrags 0
Whiten all surroundings at 800x600 resolution r_lightmap 1

*Turrets (standing): Avoid lasers and toss a grenade from cover (preferably a corner)

*Turrets (operated w/bunker): Try to run up to a pile of sandbags and duck (if you can't get behind a corner), then if you are safe, throw a grenade into one of the sides - it will kill the soldier operating it.

*Rocket turret (In the "On A Track" level): Real easy to avoid, but can be deadly. Your best bet is to duck behind the controls of your cart and wait to pass it. When you do, shoot the soldier and watch him explode

*Sniper: If you are being struck by bullets and can't see the assailant, it's probably one of these suckers. If you die, reload and pay close attention to the walls. If you see camouflage, get close and toss a grenade into his perch.

*Alien w/hive hand (can't remember the name - it's a big guy): If it fires a multitude of wasps at you, try to run away and duck behind a corner to avoid them. Your best weapon bets are the magnum, the laser, and the crossbow. It's easy to defeat by itself, but in groups they get to be really frustrating.

*Alien w/blue shell, red eye, and the ability to shoot fire from his hands(also forgot his name): This guy's thankfully not very common (I've only seen him twice) but is just plain evil. Rockets, grenades, anything that explodes will be your weapons of choice. Even a full rocket launcher won't take him out, so a lot of grenades are necessary.

Tiny bugs (when found in a pod, can be used as weapons): In the "Forget Freeman!" level, these guys will be in hovering little sacks that rupture when you come into contact. Your best bet is to run away to some place with light, then pull out the pistol and shoot them as they approach.

Hydra (also a boss): These guys will either be in a three-pack (first appearance) or alone (in the desert). You can't kill them with your weapons, so distract them by tossing a grenade to some far-off side where they can hear it, then run like hell to reach your destination before they hear you and kill you (any method of walking will not help you with stealth - you have to distract it)

Fish monster: Your weapon of choice is the crossbow (and you get it before you fight one - convenient). Pull it out and wait for it to charge at you, then fire an arrow and get out of the way. On occasion, come up for air, but be careful when you come down - you never know where it is. Repeat this strategy until it goes belly-up

The final boss, Nihilanth, can be a pretty big pain-in-the-bootay with his portal attack that sucks you into another area filled with enemies.
Of course, those enemies get tougher and tougher, so to not deal with this headache (so much), follow this strategy:
*Nihilanth always puts his hands together (as if in prayer) before he attacks with either a portal or a bunch of lightning balls
*So whenever he puts his hands together, duck behind one of the tall rock spikes.
*Keep in mind, however, that if the portal hits the rock, an alien will spawn from it (no big deal, though)

Well, do you want to now how to get 100%. There isn't alot of water in the black masa. So if you find a pond, of water you can jump and swim under water. If you have 99% or lower jump into the water. Nearly drowned and come up for Air. AND IT WILL RISE TO 100%. This works to on: Blue shift, team fortress classic( diffently),half life source, half life 2, half life death match, and all sorts of mods, an MORE!!!!! Have fun!!!

First you need a crossbow and another gun.Second take out the other gun and save with it out.Third take out the crossbow and put it on sniping mode.Fourth keep the crossbow on sniping mode and load back to the other time when you saved it.Finally no matter what gun you hade it on it will be on sniping mode.

After you shoot the missle in single player mode, turn on no clip, and chase it. But let it go completly out first then leave. As soon as you get out of the area, turn off noclip, and turn on your flash light. You are now in a hidden room.

In the 3rd part of 'Interlooper' , where you see a Garg (a huge monster who can burn you) crushing rocks ans stones to be able to pass through, there will be a small hole behind. When you enter it, you will find a small waterfall, and plenty of water on the floor. When you step into it, your health will recover gradualy.

Before entering the hole, look in the direction where the Garg crushes the huge rocks. You should be able to see a sort of staircase, but smoother than a staircase. In fact, it can be described as a slope. It'll be on the left, stuck to the wall.

Climb on it, and when on top, look to the right. you'll see a tiny lighted room with med-kits and ammunition packs in it. Duck, and crawl into it.

When you finish the office complex chapter save as the elevator doors are closing (incase it doesn’t work). Take out your pistol, and quickly run passed the metal door to the LEFT side of the bullet proof glass where the silo door button is. The scientist should be shouting about opening the silo door. As soon as he stops running, shoot him once in the chest, so not to kill him. He should stop yelling and run away from you (towards the elevator), and when he passes the metal door it will open! Inside you will hear the voice of the scientist who spawns in the room at the end of the chapter, and you can now open the silo door.

Pros:
Skip a large portion of the game, good for speed runs
Maximizes your health (there are two health stations

Cons:
Miss out on the MP5, and a few grenades.

this is kinda creepy.... only in the pc version tho.... ok... go to the training room. Insert these codes into the console: sv_cheats 1 and impulse 101. (impulse 101 gets you all the weapons) in the room with the HEV suit, jump down the ditch and you will die. OK this part works on some depending on how high your graphics card is. The screen will turn black. Use the MP5 (the machinegun) and shoot. The shots will act as a flashlight to show in the darkness G-Man standing there staring at you. This scared the crap out of me XD

Console Codes

First, enable the console. Then, type the proper code into it to get the desired effect.

Code - Effect

give ammo_9mmclip 17 ammo for the glock pistol.
give ammo_357 Ammo for the 357 magnum.
give ammo_9mmbox Ammo for the glock pistol.
give ammo_crossbow Crossbow ammo.
impulse 203 Delete Targeted Enemy
r_fullbright 1 (Replace 1 with 0 to turn them back on.) Eliminate Shadows
give weapon_handgrenade Gives you some hand grenades.
give item_healthkit Gives you some health.
give weapon_tripmine Gives you some laser tripmines.
give weapon_snark Gives you some snarks.
give weapon_357 Gives you the 357 Magnum.
give weapon_crossbow Gives you the crossbow.
give weapon_crowbar Gives you the crowbar.
give weapon_9mmhandgun Gives you the glock pistol.
give weapon_gauss Gives you the guass rifle.
give item_suit Gives you the HEV suit.
give weapon_hornetgun Gives you the hornet gun.
give weapon_mp5 Gives you the MP5.
give weapon_rpg Gives you the rocket launcher.
give weapon_shotgun Gives you the shotgun.
impulse 101 Instant Weapons, Ammo, and Armor
/god Invincibility
notarget Invisibility
give ammo_mp5grenades Mp5 grenade ammo.
give ammo_mp5grenades Rockets for the Rocket Launcher.
sv_gravity # (Lower numbers gives less gravity, higher gives more. Normal is 800.) Set Gravity Level
impulse 102 Spawn Gibs
impulse 76 Spawn Marines
chase_active 1 Third Person
thirdperson Third Person View
noclip Walk Through Walls


Impulse Codes
After activating the conlse, press tide (~) and enter the following.
Code Effect
impulse 109 Control onscreen monsters. This code may not work in versions of the game.
impulse 76 Creates a human grunt. Be careful, this can crash the game.
impusle 202 Creates blood infront of you, like spray paint.
impulse 203 Deletes target NPC or monster from the game.
impulse 195 Displays AI node information
impulse 105 Enemies can't hear you
impulse 101 Get all weapons and armor. Enter again for more amo and/or armor.
impulse 104 Lists global entities
impulse 102 Spawn gibs.
impulse 103 While looking at amonster, displays stats.
impulse 106 While looking at an object, displays model/sprite stats.
impulse 107 While looking at an object, displays the texture name.


Items from the console
Go to the start menu, then go to all programs, then go to accessesories, then click on command prompt. Select you Half-Life directory and type hl.exe -console then Half-Life should open. Start a new game then press the ` (tilde) key then type in these codes:
Code Effect
give ammo_357 357 magnum ammo
give weapon_mp5 Gives you a MP5
give weapon_python Gives you a 357 Magnum
give weapon_crossbow Gives you a Crossbow
give weapon_crowbar Gives you a Crowbar
give ammo_glockclip Gives you a Glock pistol clip
give weapon_gauss Gives you a Guass Rifle
give weapon_hornetgun Gives you a Hornet Gun
give weapon_tripmine Gives you a Laser Trip Mine
give weapon_9mmhandgun Gives you a Pistol
give weapon_rpg Gives you a Rocket Launcher
give weapon_satchel Gives you a Satchel Charge
give weapon_shotgun Gives you a Shotgun
ammo_crossbow Gives you Crossbow ammo
give weapon_handgrenade Gives you some Hand Grenades
give ammo_mp5grenades Gives you some MP5 Grenades
give weapon_egon Gives you the egon!
give ammo_rpgclip Gves you a Rocket
give item_healthkit Health
give item_suit HEV Suit
give ammo_9mmclip Pistol clip


Super Jump
You go to console and you have to type
X=any number,0-999
sv_gravity X
You should have only one space after gravity and before the number
It shoud look like this
sv_gravity 111


Code Effect
sv_gravity 888 The normal jump
sv_gravity 0-999 You are now the master
sv_gravity 0 You can float and walk in air for amount of time.Highest jump
sv_gravity 999 You can't jump at al