Half-Life: Opposing Force

Half-Life: Opposing Force

Developers: Gearbox Software, Valve
Publishers: Sierra Studios (retail), Valve (Steam)
Platforms: Windows, Mac OS X, Linux
Released in US: November 18, 1999
Released in EU: November 29, 1999

This game has unused animations.
This game has unused areas.
This game has a hidden developer message.
This game has hidden developer credits.
This game has unused graphics.
This game has unused models.
This game has unused items.
This game has unused sounds.
This game has unused text.
This game has regional differences.
This game has revisional differences.

This game has a prototype article

This game has a prerelease article

To do:

A Press Demo has been found
Unused sitting animations in the model for the grunt ally entity, one of which consists of the grunt sleeping upright. Might be related to an unused voiceline, see here.
Document the 25th Anniversary Update changes for this game.

Half-Life: Opposing Force is an expansion to Half-Life. You are Adrian Shephard, one of the soldiers sent to "silence" Black Mesa's staff. However, your transport plane is shot out of the air before you can land, and you awaken soon before the military pulls out. Trapped with stranded fellow soldiers and what remains of Black Mesa's staff, you must escape the facility while fighting off against the Black Ops seen in the first game (now augmented with male troopers as backup) and the mysterious Race X. Thankfully, you have ~~the power of friendship~~ a lot of powerful new weapons to help deal with the new foes.

Sub-Pages

Prototype Info

Prerelease Info

Unused Sounds
"To win the game, you must kill me, Randy Pitchford."

Unused Models
A dead Gordon Freeman? No way!

Unused Animations
Stab, stab, stab...

Unused Behavior

The Security Guards, Otis Security Guards and Scientists support a newly added key-value named "suspicious" that can be set to 1 or 0. When turned on, this makes them always act hostile towards the player or scared of them respectively, as if they were shot at. This specific behavior switch isn't used in any maps.

Half-Life's Human Grunts

The Human Grunts from the original Half-Life are still in the game and can be summoned with the cheat "impulse 76". Gearbox Software wisely decided against editing the original grunts from Half-Life, and instead, a separate ally grunt entity was made using the Half-Life grunt model early in development before transitioning to new models made by Gearbox.

When spawned, they will attack friendly soldier NPCs but not Black Ops assassins because both use the same relationship table (code that handles how entities treat each other).

Half-Life Human Grunt attacking friendly soldiers.
Half-Life Human Grunt working with a Male Black Ops to kill the player.

Unused Map content

Boot Camp signature

In the first Boot Camp level (ofboot0), there is a signature by the mapper David Michael Mertz of Gearbox with the year of creation. It's only accessible by using noclip to get past two locked doors.

Half-Life's Xen

If the player follows Gordon through the portal at the start of We Are Not Alone, they will be teleported into the chapter Xen from the original game, but will fall into the void. However, with noclip, the level can be played, and a surprising amount of it is playable.

Since the player lacks the Long Jump Module, cheat codes are required to spawn it in (or the use of noclip to fly straight to the center asteroid). With it, the player can trigger all of the assaults on the way to the main asteroid from the asteroid Gordon is on, reach the main asteroid, then kill all of the Houndeyes that roam the area and all of the items around the asteroid's perimeter (such as the Medkits). However, the ways to the center of the asteroid are blocked. Using noclip to see the core of the asteroid will reveal that the level designers stripped out everything inside it, making it impossible to activate the teleporter.

Of note is that the laser-shooting objects around the perimeter do not shoot lasers and cannot be destroyed.

Playing through Xen.
Blasting a Houndeye in Xen with the M249 SAW.
The end of the line.
The empty core room.

Multiplayer level signature

Opposing Force's version of Boot Camp still has Dario Casali's signature, as seen in the original version of the level.

Welcome to Black Mesa

The original design for of1a3's control room can be found in the map of1a4, behind the level transition brush.

of1a4	of1a3

"We are Pulling Out"

2 strange hangar structures are floating far outside of We are Pulling Out's last map, only observable via fullbright or inspecting the map file. They appear to resemble early designs of the hangars seen in the cut "Hangar" mission for Half-Life: Decay.

Friendly Fire

The chapter's starting map, of2a4, has an "entity room" with a message from the map creator asking the player what are they doing in his entity room.

Foxtrot Uniform

The map of5a2 has a small tunnel with a truck inside of it is placed out-of-bounds, which can only be seen with fullbright. The truck's textures appear to be misaligned.

Unused Graphics

Civilian Charger

An alternate grayscale version of the Ohms Power Inc. charger seen in the Bootcamp. It appears to lack lights to indicate its capacity.

Pallet

An alternate wooden pallet texture, which doesn't support transparency.

Table Message

TABLE_02 has a hidden message in its lower right corner, warning everyone to not even mess with it.

Hidden Hack Texture

If the player uses console commands to view the skybox from within the V-22 Osprey during the ending G-Man sequence, there is a hidden message on the upper skybox texture. The message reads:

HACK HACK HACK
 ALL DAY LONG.

HACK HACK HACK
 WHILE I SING
  THIS SONG.

This poem is a reference to an Adam Sandler song, The Beating of a High School Janitor. This can also be found by viewing the game's files.

WON Logo

In WON versions of Opposing Force, in the pak0.pak folder "gfx\shell" there is a graphic called "won_logo.bmp".

Barnacle Tongue

Under the name "_tongue", there exists a pink human-like tongue sprite, possibly meant for the barnacle grapple weapon. The used sprite is named "tongue".

Unused (_tongue.spr)	Used (tongue.spr)

Computers

The files contain three sprite series called "comp". The first one, called comp_a, shows one of the servers from the original game's Apprehension, with and without a hole in it (which can happen in the level the server appears in). Comp_b is a smaller version of comp_a. Comp_C shows a traditional 90s desktop computer with two variants. The first variant has a hole in the monitor and jagged bubble surrounding it, while the second one has the damaged computer from the first variant with a No sign over it.

The graphics have the correct colors needed to be on the HUD.

comp_a
comp_b
comp_C

CTF HUD Graphics Message

The graphics for the HUD icons in CTF mode have "Opposing Force Capture The Flag" crudely doodled at the bottom of them. This message is never shown in-game.

Happy Face

The unused happy face from the original game's HUD files makes a reappearance in Opposing Force.

Nuclear Explosion

Three graphics for a small nuclear explosion are in the game's files. Two of them are the same, while the third one has a transparent background.

While a nuclear explosion does happen at the end of the game, the player is never able to see the explosion itself.

Nuclear explosion with blue background.
Nuclear explosion with transparent background.

Sprites

There are three unused sprite sets with the name "sprite". The first one is a literal sprite, while the second one is an orb with a large star-like shape in the center of it, similar to the floating orbs seen in the last scene of the game. The third one is a duplicate of those same orbs.

The literal sprite.

Unused Text

Disabled Developer Credit

Within titles.txt, there's an additional developer name among the names displayed during the intro. It's additionally mentioned inside the map logic for the intro, but is not timed correctly to be displayed.

CR9
{
Tollbooth Willy
}

This also happens to be a reference to another Adam Sandler song, Toll Booth Willie.

(Source: Marphy Black)

Placeholder

Gearbox originally created three PAK files for the game's content. For whatever reason, one of them (pak0.pak) contains a file called, "placeholder.txt":

:P

The PAK files were removed following Steam's SteamPipe updates, meaning they can only be found in the retail release.

Developer Configuration Files

In the CD release, there exists configuration files from Opposing Force developers that make references to unused maps and hidden console commands. These files can be found in "pak0.pak".

bind "F2" "map of1a3"
bind "F3" "playdemo ectsdemo1"
bind "F4" "map of2a5dmo"
bind "F5" "playdemo ectsdemo2"

Hidden Console Commands

Haiku

By typing "haiku" into the console on any map, a haiku will be written across the screen. The way it works is that it takes several random sentences and botches them together to form a unique haiku every time.

A complete list of phrases is provided at Half-Life: Opposing Force/Haikus.

so what if I sweat, programmer's head on a stick, you have been a fool.
anonymous nub, frictionless, massless mormon, let's tease the weasels.
some quick goat thinking, candy corn chicken fetus, i have to call chuck.
white cotton panties, programmer's head on a stick, i must escape it.

Impulse 99

This command (which is also in Half-Life) displays several company logos and the game title in the upper right corner. Only used for pre-release videos and screenshots, it was modified by Gearbox for Opposing Force. The only difference from Half-Life is the addition of the Gearbox and Half-Life: Opposing Force logo. This was used during E3 1999, seen in most gameplay footage.

This command will not function at resolutions above 1024x768.

Half-Life: Opposing Force logo.
Gearbox logo.
Impulse 99 in-game.

Revisional Differences

Main Menu

The main menu's layout underwent the same changes that the original game did, which removed the unique descriptions for the main options and the little animated "Opposing Force" logo that had soldiers and an Osprey going through a desert in it.

The background graphic is mostly the same, but the Steam version replaces the lambda logo with an image of Adrian holding a green flag and Gordon holding another flag to show off the CTF mode.

Pre-Steam versions	Current Steam release

Console

And like the base game, the console was changed to dropping down when activated to having its own window.

Pre-Steam versions	Current Steam release

Oddities

"The Package"

The two Alien Slaves/Vortigaunts encountered at map of6a2 of chapter "The Package" are supposed to be Shock Troopers, judging from their internal entity names. Gearbox used the default Half-Life enemies as stand-ins for the new ones they wanted to implement during development, and possibly forgot to replace these two fellas. This is also proven by how these Vortigaunts can self-teleport to the player's position in a scripted sequence - an ability only Shock Troopers possess.