Codes
Start Half-Life using "hl.exe -dev -console -game gearbox.
You may do this by modifying the windows shortcut properties for Half-Life OpFor and adding "-dev -console -game gearbox" to the end of the "Target" (or file to run).

The following commands are available in console:


IMPULSE 101 - Give all weapons and ammo.

/GOD - god mode.


/NOCLIP - walk through walls/fly.


/MAP xxxx - go to map xxxx.

/GIVE xxxx - give item xxxx.

/GIVE WEAPON_X - give weapon X, where X equals:

GRAPPLE
KNIFE
PIPEWRENCH
EAGLE
M249
SNIPERRIFLE
DISPLACER
SHOCKRIFLE
SPORELAUNCHER

Hidden Audio
Approach the Boss of Opposing Force to hear backwards audio composed of the phrase "To win the game you must kill me Randy Pitchford" when played correctly. Randy Pitchford is the leader of the development team at Gearbox Software.

Hidden Suicide Technique!
At the part where you see Gordon Freeman jumping in the portal to Xen, notice that the portal is still open for about 5 or 10 seconds. When you open the door, quickly run after Freeman and jump into the portal. Instead of landing on a platform, you will just fall and then you will see a short sequence showing how you died.

Third Person
Firstly, activate the console and bring it up during gameplay. Then, type in /thirdperson and press enter. You can now play Opposing Force in the third person.