Half-Life: Game Of The Year Edition Codes -

Cheat mode:
Load game with the command line: hl.exe -dev -console. Then, press ~ if the orange text on the screen does not disappear. During gameplay, press ~ to display the text prompt and type in sv_cheats 1. Press ~ and enter one of the following console commands to activate the corresponding cheat function.

Effect	Code
God mode.	/god
Adjust gravity	sv_gravity <-999 - 999999>
All weapons and ammo	impulse 101
Developer mode on	developer 1
Verbose developer mode	developer 2
Developer mode off	developer 0
Suicide	kill
Map select1	/map <map name>
No clipping mode	/noclip
Obtain item2	/give <item name>
Opponents ignore character	/notarget
Third person view	/thirdperson
Return to first person view	/firstperson
Auto-reload enabled	+reload
Auto-reload disabled	-reload
See things brightly without flashlight	lambert -1.0001
HEV suit, weapons, and ammo	impulse 101
Spawns gibs and blood	impulse 102
Monster stats, while looking at monster	impulse 103
List global entities	impulse 104
Silent player	impulse 105
Model/sprite stats, while looking at target	impulse 106
Texture name, while looking at object	impulse 107
AI node information	impulse 195
AI node information	impulse 196
AI node information	impulse 197
AI node information	impulse 199
Delete monster or NPC from world	impulse 203

Glitch: Talk to dead security guard:
Get the HEV suit and enable the impulse 101, impulse 105, and notarget codes. Reactivate the cheat screen, and keep using the impulse 101 code until your HEV suit is full. Choose the high explosive (press 5 twice) and return to the lobby in Sector C Test Labs, where the security officer is on the computer. Go behind the desk and throw a high explosive under the desk. Walk anywhere you want, but not past the loading point, then detonate it. Walk back and the security officer should be on the desk. Talk to him.

Glitch: Delayed death:
Enable the impulse 101, impulse 105, and notarget codes and get the Magnum. Walk up to a scientist from behind, then shoot him in the back of the head. Certain ones will make a noise, stand for about five to ten seconds, then fall and die.