Half-Life: Source: Complete Guide

A guide to Valve's 2004 Source-engine port of Half-Life: what's different from the original, a chapter-by-chapter walkthrough outline, weapons, boss strategies, and the bugs and settings worth knowing about on a modern PC.

Researched September 2026 — current as of the last Half-Life: Source update (November 4, 2013). Live games change; check the linked sources if something differs.

Should you play this version? Half-Life: Source is a direct port of the 1998 game to the Source engine — same levels and models, new physics, water and lighting. Fans generally rate it below the original: Combine OverWiki notes poor reception and bugs worsened by the 2013 SteamPipe update, and Wikipedia notes retrospective criticism for instability. Combine OverWiki also reports that Valve delisted it on November 17, 2023 (the series' 25th anniversary) in favor of the original; however, Steam's store data still returned a purchasable package when checked in September 2026, so availability may vary. If you own both, the updated original Half-Life is the recommended way to play; if you want a full remake, look at the fan-made Black Mesa (released 2020). This guide covers Source specifically, but the walkthrough applies to both.

Quick Start

Quicksave constantly. The default quicksave key is F6 and quickload is F9. Half-Life has no checkpoints you can rely on.
Crouch-jump to reach ledges. Jump then crouch mid-air to clear higher obstacles. It's needed for many platforming sections.
Charge up at wall stations. HEV chargers restore suit armor; health stations restore health. Top up before every big fight.
The HEV suit is essential. Without it (the very start) you can't pick up weapons. The suit also absorbs damage.
Watch for the long jump module. Later you get a long jump: hold crouch and press jump while moving forward.
Physics objects are new in Source. Crates and debris behave with ragdoll-era physics — occasionally helpful, occasionally buggy.
Try the HD pack only if you like it. Since 2013 an optional HD pack can be toggled in Options → Video; it swaps in the higher-detail models from the old "High Definition" add-on.
Don't rush Xen. The low-gravity jumping is imprecise; save before every jump.

What's Different from the Original

Change	Detail
Physics	NPCs become ragdolls on death and cannot be gibbed; many objects use Source physics
Water and lighting	Reflective water, improved lighting, higher texture quality
Skies	3D skyboxes replace flat bitmap skies
Sound	Many interaction sounds (buttons, doors, breakables) reuse Half-Life 2 audio; 5.1 surround support
Level tweaks	The canyon in Surface Tension was changed
Player death	The camera no longer tilts sideways; your weapon visibly drops
Models/animations	Mostly unchanged — which is the main criticism

2013 fixes

Valve's September–November 2013 updates moved the game to SteamPipe, added Mac and Linux support, added the optional HD pack, fixed a crash during the Apache helicopter fight, restored drowning sounds, set the Glock to 17 rounds per magazine to match the original, and fixed the missing HEV suit when starting at "Unforeseen Consequences" and "Residue Processing" via chapter select. Several of the Source port's quirks remain.

Controls

Action	Default
Move	W/A/S/D
Jump	Space
Crouch	Ctrl
Use (buttons, chargers, scientists/guards)	E
Flashlight	F
Reload	R
Quicksave / Quickload	F6 / F9
Long jump	Crouch + Jump while moving (after getting the module)

Scientists and security guards follow you when you "use" them — guards fight alongside you and scientists open retinal-scanner doors.

Chapter Walkthrough Outline

Half-Life has 19 chapters.

#	Chapter	What to expect	Tips
1	Black Mesa Inbound	Tram ride intro	Just enjoy it
2	Anomalous Materials	Suit up, the resonance cascade	Grab the HEV suit before leaving the locker area
3	Unforeseen Consequences	First headcrabs and zombies; crowbar	Use the crowbar on headcrabs to save ammo
4	Office Complex	Offices, first firearms, security guards	Recruit guards; watch for ceiling barnacles
5	"We've Got Hostiles"	The Marines (HECU) arrive	Take cover; grenades hurt; they flank
6	Blast Pit	The tentacle creature in the silo	Stay quiet — it hunts by sound; restore power, oxygen and fuel, then fire the rocket engine
7	Power Up	Restore power to the rail system; a Gargantua	You can't kill it with normal weapons; lure it into the electrified generator
8	On a Rail	Drive the rail cart; launch a rocket	Watch the tracks and switches
9	Apprehension	Water-filled facilities; ends with Freeman captured	Watch the water; save before the ending sequence
10	Residue Processing	Dumped in a trash compactor and starting without weapons; conveyor belts and hazards	Careful platforming; quicksave often
11	Questionable Ethics	Labs and more alien weapons	Use scientists to open doors
12	Surface Tension	Outdoors: Marines, tanks, an Apache helicopter and another Gargantua	Call in the airstrike on the Gargantua; RPG the helicopter
13	"Forget About Freeman!"	Marines everywhere, underground	Laser trip mines and satchels are great here
14	Lambda Core	Reactor cooling and teleporter puzzles	Map the teleporters mentally; save before each jump
15	Xen	Low-gravity alien world	Long jump carefully; save before each leap
16	Gonarch's Lair	The Gonarch boss	Keep moving, use explosives and heavy weapons
17	Interloper	Alien factory	Vortigaunts and alien grunts; conserve Gluon ammo
18	Nihilanth	Final boss	See boss tips below
19	Endgame	Ending sequence	Your choice decides the ending

Weapons

Weapon	Use
Crowbar	Headcrabs, crates, saving ammo
9mm pistol (Glock)	Early all-rounder; 17-round magazine since the 2013 update
.357 Magnum	High-damage precision
Submachine gun (MP5)	Main automatic weapon; has a grenade launcher
Shotgun	Close range; secondary fire shoots both barrels
Crossbow	Scoped; silent and strong, fires underwater
RPG	Laser-guided rockets for tanks and helicopters
Tau Cannon	Can charge shots; charged shots pierce walls and can propel you
Gluon Gun	Beam weapon; shreds almost anything, eats ammo fast
Hivehand	Alien bio-weapon with regenerating ammo
Hand grenades	Rooms and groups
Satchel charges	Remote-detonated explosives
Laser trip mines	Traps for Marines
Snarks	Throwable alien creatures that attack whatever's nearest

Enemies

Enemy	Tips
Headcrabs / zombies	Crowbar; zombies are slow, back-pedal while swinging
Barnacles	Ceiling tongues that pull you up; shoot them or crowbar them when lifted
Houndeyes	Sonic blast; kill before they gather
Bullsquids	Spit acid; strafe
Vortigaunts	Electric attacks with a visible charge-up; interrupt with gunfire
Alien grunts	Tough; use the shotgun or explosives
HECU Marines	Smart flankers with grenades; fight from cover
Black Ops assassins	Fast and acrobatic; watch corners
Gargantua	Don't fight it head-on; use environmental kills

Boss Tips

The tentacle (Blast Pit): it reacts to sound. Walk, don't run, and throw grenades to distract it. The solution is to restore oxygen, fuel and power, then fire up the rocket engine test.
Gargantua (Power Up): lead it into the generator's electrified area once it's powered.
Surface Tension Gargantua: call in the airstrike to deal with it.
Gonarch: keep moving, stay away from its baby headcrabs, and hit it with RPG, Tau or Gluon damage when it exposes itself.
Nihilanth: destroy the golden energy orbs that protect it, dodge its teleport attacks, and then shoot its exposed head. Destroy the healing crystals around the arena so it can't recover, and use the arena's platforms to get level with its head.

Common Mistakes to Avoid

Not saving before jumps and big fights. Xen and Residue Processing will make you regret it.
Playing through the Marine sections without cover. They flank and throw grenades.
Spending Gluon ammo early. It's your trump card for the last chapters.
Fighting the Gargantua directly. Use the level's solutions.
Assuming Source is the definitive version. It's a port; the updated original and Black Mesa are often preferred.

Advanced Tips

Tau Cannon jumping: charging the Tau and firing at your feet propels you — a classic speedrun trick.
Crowbar everything cheap: headcrabs and barnacles are free kills that save ammo.
Use Snarks on groups and walk away.
Scientist escort: stay close so they don't get lost; they open retinal scanners.
Chapter select: jump to any chapter you've reached via New Game.
HD pack: if animations look off, toggle it back off in Video options.

FAQ

Is Half-Life: Source worth it over the original? Most players prefer the updated original Half-Life or the Black Mesa remake. Source adds physics and water but keeps the same models and introduces bugs.

Does Half-Life: Source have achievements? No.

Is it still for sale? Combine OverWiki reports Valve delisted it in November 2023, but Steam's store data still showed a purchasable package in September 2026. Check the store page in your region.

How do I fix the missing HEV suit when starting a chapter? That was patched in November 2013 for "Unforeseen Consequences" and "Residue Processing". Make sure your install is up to date.

How long is Half-Life? Around a dozen hours for a first playthrough, depending on how often you die in Xen.

Does it run on Mac and Linux? Yes — native Mac and Linux support was added in 2013.