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.

Code	Effect
overflow	Attempt to overflow player
assert	Causes NS to assert
crash	Crash NS
killhive	Destroy random hive for alien team
getnumplayers	Display current number of human players
editps [name]	Edit particle system
Endgame [1 or 2]	End game with victory for indicated team
stopcommandermode	Exit commander mode
buildminimap	Generate new minimap.
alert	Generate random alert
giveupgrade [upgrade code]	Get indicated upgrade
givepoints	Get points
orderself	Give orders to yourself
startgame	Immediately start game
bigdig	Instant building construction
hightech	Instant research
killcs	Kill all command stations
killall	Kill all players with your current weapon
tooltip lala	Lala tooltip
listps	Lists particle systems
spawnhive	New random hive for alien team
paralyze	Paralyzes self (as level 5 ability)
parasite	Parasites self (no damage)
testevent	Play test event
addcat [1-4]	Random upgrade category (1 for defense, 2 for offense, 3 for movement, 4 for sensory)
removeupgrade [upgrade code]	Remove indicated upgrade
removecat [1-4]	Remove upgrade category
clientrun [name]	Run a client-side script
run [name]	Run server-side script
deathmessage [weapon name]	Send test death message
setculldistance [value]	Set culling distance needed for commander mode
setgamma [1.0-2.0]	Set env_gamma level
setskin [0 or 1]	Set skin color 0 is white, 1 is black
boxes	Show bounding boxes
web	Simulate one web touch
attackcs	Slightly damage one command station
startcommandermode	Teleport to nearest command station and start commander mode
invul	Toggle invincibility for yourself.