Half-Life 2: Episode One

Half-Life 2: Episode One
Developers: Valve, EA UK (PS3) Publishers: Valve, CyberFront (JP) Platforms: Windows, Xbox 360, PlayStation 3, Mac OS X, Linux Released in JP: June 2, 2006 Released in US: June 1, 2006, May 26, 2010 (Mac OS X), June 27, 2013 (Linux) Released in EU: June 2, 2006, May 26, 2010 (Mac OS X) This game has unused areas. This game has unused enemies. This game has unused graphics. This game has unused models. This game has unused items. This game has unused sounds. This game has a prerelease article

Originally titled Half-Life 2: Aftermath, Half-Life 2: Episode One is the follow up to the original Half-Life 2, featuring pretty-looking HDR effects, more cooperation with Alyx, more physics puzzles, and red skies o' doom.

As of 16 November 2024, Half-Life 2: Episode One has been merged into base HL2 as part of the 20th Anniversary update, with its Steam store listing now removed.

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Prerelease Info

Mini Strider

The npc_ministrider is an entity available in the pre-Orange Box versions of Episode One and is an early version of the Hunters seen in Episode Two. It was used for the Mossman Arctic transmission sequence, but when Episode One was updated to the Orange Box version of the engine, npc_ministrider was removed, with the one used in the scripted scene being replaced for a npc_furniture entity. Since npc_ministrider was never released in any SDK code, the original NPC now only exists in old, pre-Orange Box versions of Episode One's engine.

npc_ministrider

The mini-strider lacks the ability to fire fléchettes, and is vulnerable to explosives and energy orbs.

Scrapped Sequences

Stripped Soldier

During the Citadel escape chapter, Alyx and Gordon come across the lifeless body of a stripped Combine Soldier. Frustrated, Alyx expresses her anger by mocking the soldier, and kicking the corpse off the edge. This scene has two variations.

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Subway Map

After emerging from the underground, Alyx was originally meant to point out a map in the room and remark that they still had a long journey ahead before reaching their destination.

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Combine Outpost

During the segment where the player storms a Combine Outpost, Alyx jokes about breaking "about 50 Combine regulations." While this line remains in the game, she was originally intended to humorously list a few of the rules they had violated off the top of her head.

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Exploding Console

Matt T. Wood, a former level designer and choreo director at Valve, has a developer commentary describing a scrapped sequence between Alyx and Gordon that was meant to take place before the puzzle room with the Stalkers and Rollerminers.

Developer Commentary

Transcript:

"In an early version of this map, Alyx led the players through the whole thing. To make Alyx seem less omniscient, we had her access a console here to get her bearings. It exploded, which helped drive home the point that the Citadel was in bad shape, but generally, it was a long pause in the action without a lot of payoff. After we made the high-level decision to have Alyx follow the player, this entire scene became irrelevant, and we happily cut the whole thing."

weapon_proto1

In ep1_pak_dir.vpk, inside of scripts folder, there is a weapon script for a prototype weapon called "weapon_proto1". More information about the weapon and its specifications are here.

Unused Map

ep1_citadel_00_demo

Judging by its filename, a version of the starting map made for a demo version. The released game does not have a demo available. Loading the map via developer console causes the game to crash, and decompiling the .bsp file via programs like BSPSource spits out errors. This map was accidentally released to the game with the SteamPipe update.

wasteland_test

A map called wasteland_test.bsp was included in an update to Episode One in May 2013. It takes place in a barren, rocky canyon, infested with Fast Headcrabs and Antlions. The map features an apparent Resistance base, two small outposts - each with three supply crates, a nonfunctional Emplacement Gun, and two rebels - one manning the gun, other, armed, providing medkits, a hill in the middle, and three Striders at the end, non hostile unless attacked, and separated from the main area by a deep ravine. The player spawns in the Resistance base guarded by four reprogrammed Combine Sentry Guns, and containing two Health and two Suit Chargers, as well as three supply crates and an infinite grenade crate; a reusable TNT trap is located near the base. He is greeted by an on-screen message from Alyx, who says that she needs six petrol cannisters, scattered around the map, to fuel a chopper, and that the player has to "find them and put them in the receptors by the cave entrance". Although Gordon has the Scout Car at his disposal, he is attacked by a never-ending wave of Combine Soldiers and Elites deployed by Dropships. When the player manages to collect all of the canisters, Alyx says that she needs to "make a few more repairs", and tells Gordon to "hold them off" for as long as he can.

Vortex Hopwire Grenade

This "weapon", also nicknamed the Black Hole Grenade, can be spawned through the console. It is very powerful, drawing everything nearby into it before collapsing and killing enemies instantly. However, it is glitchy and has an unfinished model; as it re-uses the Rollermine model as its worldmodel and the Frag Grenade's viewmodel. According to Episode Two's commentary track, this would later become the Magnusson Device.

If used too close to Alyx, it can kill her and spawn endless ragdoll copies, and often crashes the game to desktop. Later in few updates, code and scripts for this weapon were removed, however, it can still be spawned via console commands in Portal.

Unused Textures

Early blue Vortigaunt texture

This is (presumably) an early texture for the vortigaunts seen in the intro.

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Chapter 6

This GUI texture is for the obsoleted 6th chapter named Coming Soon. It shows Alyx hanging on from a metal railing from a train, something that can be seen in the Episode 2 teaser found in the game files.

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squashed parts.vtf

Found in materials\models\antlion_grub, this is an early version of the grub's squashed parts. Note that it doesn't have an underscore, despite being 2 words (squashed parts).

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vortring

A sprite for the vortigaunt ring.

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sky_day03_06c

An alternate variant of the skybox used in d3_breen_01 from Half-Life 2.

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sky_ep01_01

A daytime skybox with the red ring seen in the other skyboxes. Its use is unknown, though.

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Antlion Guard

Two Antlion Guard textures can be found within Episode One's files. These textures give the Antlion Guard a blue-ish colour. These could be early versions of the Antlion Guardian's textures from Episode Two.

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  Body.

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  Legs.

Combine Monitors

Various temporary textures of Combine Monitors can be found in materials\effects. These consist of photos of the main characters. Gordon's picture seems to be taken from concept art.

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  A human skeleton and what looks to be a computer chip.

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  Eli.

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  Alyx, Gordon and a random rebel.

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  Same as before, but Alyx's picture is replaced with a picture of Judith Mossman.

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  Mossman.

Unused Model

models/props_outland/pumpkin01_explosive.mdl contains an untextured pumpkin from an early build of Episode Two.

Unused Dialogue

To do: Add citizen voice lines correlating to Alyx's voicelines about greeting citizens. Alyx voice lines for a scrapped sequence involving Alyx operating a powerbox.

G-Man

There are various soundscripts located in Half-Life 2: Episode One that are pre-loaded, but whose respective sound files were omitted in versions after the preload release. The G-Man is one example of this. Here are various lines from the intro, and his only appearance in the game since the Vortigaunts hinder him from getting to talk to Gordon. Seemingly, he was to speak with Gordon in early revisions before being cut off, whereas in the final he is instead stopped from even initiating conversation.

Sound File	Dialogue
	Oh no, Freeman, come back. Come back here, now.
	Get back here.
	laughter
	Oh! Not for long.
	Not this time.
	Snarling
	Well...well shit.
	So nice to have you with us, Mr. Freeman.
	Get back where you belong, and forget about all this until-
	We meet-
	Again.
	Again.

Alyx

Sound File	Transcript	Notes
	"Unlike the fucking soldiers who volunteer for what they get.	Alyx has a small number of unused pieces of dialogue involving the Stalker train that she and Gordon ride to get out of the Citadel, where she expresses fear for the Stalkers. In the developer commentary, Bill Fletcher mentions her reactions to the Stalkers went through a number of iterations. In very early versions, Alyx was frightened by the Stalkers. This didn't work since it clashed with her earlier reactions to them in the Citadel. In the second revision, Alyx expressed anger at the Stalkers' predicament, which did not work since Alyx's transition from generally upbeat to blind rage was too sudden. Ultimately, through "rewrites and rigorous testing", the team found the right tone for the scene - a simmering anger level that was more in tune with the situation.
	"Here. Get yourself patched up."	These lines show Alyx was (presumably) meant to give medkits to the player.
	"Here, have a medkit."
	"Oooookay."	These voice lines were meant to be responses to the unused citizen voicelines. The only one used is al_greet_cit16.wav for a scripted sequence.
	"Uh, right... Can we keep moving please?"	Ditto.
	"Aren't you gonna speak up for me, Gordon?"
	"Not if we don't get moving, come on!"
	"Well, it doesn't look good. But Gordon here has worked miracles before."
	"Uhhh... I hate to spoil a reunion, but we really have to get moving."
	"Not for much longer if we don't get outta here."
	"I sure am! (laughs) Let's go."
	"Yeah, and that's Dr. Freeman in the suit."
	"And you probably know we gotta get going."
	"And trouble's right behind me."
	"We'll... help however we can."
	"Yep."
	"We stayed behind to get you moving, come on!"
	"I'm the person who's telling you to get moving!"
	"Ummm... Yeah, right. Let's go!"
	"He'll be here later."
	"A better question is: Why aren't you at the trains yet? Huh? Let's get moving."
	"We didn't make it yet, come on!"
	"Gordon's... a man of few words."
	"Gordon's free to say whatever he wants. ...Gordon?"
	"Say again? Never mind, let's move."

Barney Calhoun

Sound File	Dialogue	Notes
	The best thing you can do is run defense.	Barney was originally meant to say these lines when Alyx and Gordon meet up with him at a Resistance safehouse in the Urban Flight chapter.
	Ammo's in short supply; a lot of the citizens are unarmed at this point.
	Okay then. You take care of yourselves. I'll see you out there.	Barney was meant to say this when Alyx and Gordon are about to leave the Resistance safehouse.
	Dr. K's in fine fettle, isn't he?	Barney was supposed to comment on either Alyx or Gordon about Isaac Kleiner's condition either during the Urban Flight or Exit 17 chapters.
	Oh, you're kidding me. A Strider? In here?	Meant to be used for a Combine Strider battle in the first section of the Exit 17 chapter.
	Okay, where the hell did that strider come from? I thought they'd all hightailed it out of town by now.
	Hey, see if you can bring that strider to its knees, buddy.
	Good job knee-capping that strider!
	Are you crazy? Er, well, don't answer that.	Barney was supposed to say this if Gordon was to interact with him when under fire with a tough enemy entity during the first section of the Exit 17 chapter.
	A gunship! Well this is one hell of a wrinkle.	Lines for a Combine Gunship battle in the Exit 17 chapter.
	That's one less gunship in the world!
	Okay, we've gotta take out that armored personnel carrier or no one will be able to get through.	Barney was supposed to say this when encountering a Combine A.P.C. during the Exit 17 chapter.
	Oh hell, it looks like that soldier found himself a rocket launcher.	Barney was supposed to say this when spotting an Overwatch Soldier equipping a Rocket Propelled Grenade. In-game no Combine Soldier is wielding an RPG.
	Oh well...I don't have a trophy room anyway.	Barney was to say this if Gordon managed to defeat a tough hostile entity during the Exit 17 chapter.
	Good. Now, to catch up on those beating quotas.

Unseen details

During the arctic transmission, there are two details that go completely unseen without the use of cheats.

• Outside the base, the game spawns two elite Combine soldiers along with a standard Combine soldier positioned outside. This soldier is only visible through the use of cheats or, if developer mode is enabled, by activating the commentary note that talks about the room. Thanks to the new camera angle provided by the node, the player is able to spot the soldier outside.
• Inside the building, there is an empty room to Mossman's left. In this space, the game spawns an invisible NPC responsible for delivering dialogue for the rebels.

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