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.
| 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 select<SUP>1</SUP> | /map <map name> |
| No clipping mode | /noclip |
| Obtain item<SUP>2</SUP> | /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.