Half-Life: Walkthrough & Survival Guide

A chapter-by-chapter guide to Valve's 1998 original: weapons, the harder boss fights, movement tricks, and how to get the best version running today after the 25th Anniversary Update.

Researched September 2026 — current as of the Steam build with the 25th Anniversary Update (November 2023) and its follow-up patches (latest October 2, 2024). Live games change; check the linked sources if something differs.

Quick Start

Save often. Quick save is F6 and quick load is F9. Half-Life has instant deaths (falls, crushers, snipers) and autosaves can put you in bad spots.
Play the Hazard Course from the main menu if you're new. It teaches the ladder, jump, crouch, and swimming controls the game assumes you know.
Use the chargers. Wall-mounted health chargers restore health and HEV chargers restore suit armor. Hold Use on them.
Armor absorbs most damage. Keep your HEV suit charged. Armor matters as much as health.
Crouch-jump (jump, then crouch in mid-air) to reach higher ledges and vents.
Don't fight everything. Marines (HECU grunts) flank and throw grenades. Retreat around corners and let them come to you.
The crowbar breaks crates and vents. Supply crates often hold ammo and batteries.
Flashlight is F. Keep it on in dark areas, since it drains and recharges.

Controls (PC default)

Action	Key
Move	WASD
Jump / crouch	Space / Ctrl
Use (buttons, chargers, scientists and guards)	E
Flashlight	F
Primary / secondary fire	Left / right mouse
Reload	R
Quick save / quick load	F6 / F9
Long jump (after getting the module)	Crouch + jump while moving

Anniversary Update settings worth turning on: Allow widescreen Field of View (fixes the FOV on modern monitors), Enable texture filtering (smooth or crisp textures, your choice), and Lower Input Latency (syncs CPU and GPU to cut input-to-display delay). HUD scaling now works at high resolutions. Controllers are supported in the menus.

Weapons

Weapon	Primary / secondary	When to use
Crowbar	Melee	Crates, vents, headcrabs. Saves ammo.
9mm Pistol	Semi / fast fire	Early game and long-range taps.
.357 Magnum	Heavy revolver	One-shots grunts to the head. Save it for marines.
Submachine Gun (MP5)	Auto / grenade launcher	Main workhorse. The grenade launcher clears groups and turrets.
Shotgun	Single / double blast	Close range, and very strong against marines.
Crossbow	Bolt / zoom	Silent sniper. Kills underwater enemies.
RPG	Laser-guided rocket	Helicopters (Apaches), tanks, Gargantua support.
Tau Cannon	Shot / charged blast	The charged shot goes through thin walls. Charging while looking down launches you ("Gauss jump").
Gluon Gun	Continuous beam	Top damage. Eats uranium ammo fast. Obtained in Lambda Core.
Hivehand	Homing hornets / rapid	Infinite regenerating ammo. Good backup.
Hand Grenade	Throw	Flushes marines out of cover.
Satchel Charge	Throw, then detonate	Remote traps.
Laser Trip Mine	Wall-mounted	Ambushes and defending chokepoints.
Snarks	Throw	Chaotic little biters. Throw them at groups.

Chapter Walkthrough Outline

#	Chapter	Key notes
1	Black Mesa Inbound	The tram-ride intro. No combat.
2	Anomalous Materials	Put on the HEV suit (Gordon's locker area) and start the experiment. It goes wrong.
3	Unforeseen Consequences	Crowbar, headcrabs, zombies. Find the pistol and head for the surface.
4	Office Complex	Zombies, vents, and houndeyes. Watch for electrified water.
5	"We've Got Hostiles"	The HECU marines arrive. Tripmine hallways. Use the shotgun and MP5 grenades.
6	Blast Pit	The tentacle boss. It hunts by sound, so move quietly (walk or crouch) and throw grenades to distract it. Turn on oxygen, fuel, and power, then fire the rocket test engine to burn it.
7	Power Up	A Gargantua you can't kill with bullets. Restore the generator, then lure it onto the electrified area.
8	On A Rail	A long tram-rail network. Clear marines, flip track switches, and launch the satellite rocket.
9	Apprehension	Captured by marines. Watch out for the ichthyosaur in the water. Use the crossbow underwater.
10	Residue Processing	Waste-processing platforming with conveyors and crushers. Save before every jump.
11	Questionable Ethics	Labs full of alien specimens and marines. Get the Tau Cannon. Scientists open doors.
12	Surface Tension	The longest chapter: outdoor fights, an Apache helicopter, tanks, and a Gargantua you take out with an airstrike. Snipers and minefields. Watch where you step.
13	"Forget About Freeman!"	Marines vs aliens. Let them fight each other.
14	Lambda Core	Teleporter puzzles and reactor coolant. You get the Gluon Gun and the Long Jump Module.
15	Xen	Floating islands and low gravity. Master the long jump here.
16	Gonarch's Lair	The Gonarch (the giant headcrab mother). Stay mobile, use explosives and the Gluon Gun, and follow it down through the arena as it retreats.
17	Interloper	Alien slave colonies and Controllers. Conserve ammo.
18	Nihilanth	The final boss (see below).
19	Endgame	The G-Man's offer.

Nihilanth strategy

Destroy the three healing crystals around the arena first. Until they're gone, the Nihilanth regenerates.
Use the jump pads to reach higher levels. Watch out for its teleport orbs, since getting hit can send you to a side area you have to fight back out of.
When its head opens, shoot inside it. The Gluon Gun, RPG, or Tau Cannon charged shots work best.
Keep moving. Standing still gets you hit by its energy balls.

Movement Tricks

Crouch-jump: Jump, then hold crouch in mid-air to reach higher ledges and vents.
Long jump: With the module (Lambda Core onward), crouch and jump in quick succession while moving forward.
Ladders: Look up or down while you hold forward. Press jump to let go.
Gauss (Tau) jump: Charge the Tau Cannon's secondary fire, look straight down, and release to launch upward. Speedrunners use it everywhere.
Bunny-hopping: Speedrunners chain jumps for speed. How well it works depends on the build and settings, so treat it as an advanced trick rather than something you need.

Enemies Quick Reference

Enemy	Threat & counter
Headcrab	Leaps at your face. Crowbar or pistol.
Zombie	Slow melee. Shotgun or crowbar.
Houndeye	Sonic blast in packs. Kill them before they charge.
Bullsquid	Spits acid. Keep your distance and use the MP5.
Vortigaunt (Alien Slave)	Charged electric bolt. Strafe and shoot during the charge-up.
Alien Grunt	Tanky, fires hornets. Magnum or shotgun.
HECU Marine	Flanks and throws grenades. Hold corners and use the shotgun.
Black Ops assassins	Fast, jumping female assassins. Shotgun at close range.
Controller	Floating psychic enemies in Xen. Use the MP5 or Hivehand.
Gargantua	Near-immune to small arms. Use the environment or heavy explosives.

Running Half-Life Today

The 25th Anniversary Update (November 2023) added Half-Life: Uplink (the original standalone demo), four new multiplayer maps (contamination, pool_party, disposal, rocket_frenzy), three restored maps (doublecross, rust_mill, xen_dm), Steam Networking for easy invites, Steam Deck verification with the native Linux runtime, widescreen FOV, texture filtering, and a reskinned menu. Most original GoldSrc mods work again.
Mods not launching? Valve's own advice after the update: if a GoldSrc mod has compatibility problems, switch Half-Life to the steam_legacy beta branch (Steam > Half-Life > Properties > Betas) and switch back afterwards.
October 2, 2024 patch: fixed HLTV crashes, a memory leak from repeatedly changing brightness/gamma, and enabled large-address-aware memory for heavy mods.
Difficulty: Easy, Medium, and Hard are chosen when you start a New Game. Medium is the intended first-run experience; Hard makes marines far deadlier.
Expansions: Opposing Force (Adrian Shephard) and Blue Shift (Barney Calhoun) are separate purchases on Steam.
Remake: Black Mesa is a full fan-made remake in the Source engine, sold separately on Steam. It's a great second playthrough.
Achievements: The original Half-Life has none on Steam. Don't hunt for them.

Common Mistakes to Avoid

Relying on autosaves. Quick save before every hazard.
Charging into marines. They flank. Let them come around corners into your shotgun.
Wasting Magnum and RPG ammo on weak enemies. Save them for marines, Apaches, and Gargantuas.
Leaving the default FOV on a widescreen monitor. Turn on widescreen FOV.
Rushing Residue Processing and Xen jumps. Crouch-jump or long jump, and save before every leap.

Advanced Tips

Let enemies fight each other. In "Forget About Freeman!" and elsewhere, marines and aliens are hostile to each other.
Throw grenades around corners to flush out entrenched marines.
Use the MP5 grenade launcher on turrets and marine groups.
Gauss-jump shortcuts skip whole sections in Surface Tension and Xen.
Crossbow underwater is the best answer to ichthyosaurs.

FAQ

How long is Half-Life? About 12 hours on a first playthrough.

What's new in the 25th Anniversary Update? Uplink, new and restored multiplayer maps, Steam Networking, widescreen FOV, texture filtering, UI scaling, and Steam Deck support.

Should I play Half-Life or Black Mesa? Play the original for the authentic experience and Black Mesa for a modern remake with a reworked Xen. Both are good.

How do I long jump? Get the Long Jump Module in Lambda Core, then crouch and jump quickly while moving forward.

How do I beat the Nihilanth? Destroy its three healing crystals, then shoot into its head when it opens.

Where is Half-Life: Uplink? It's built into Half-Life since the 25th Anniversary Update. Start it from the New Game menu.

My old mod stopped working after the update. What do I do? Most GoldSrc mods were fixed by late November 2023. If one still fails, select the steam_legacy beta in Half-Life's Steam properties.

Does Half-Life have Steam achievements? No, the original Half-Life has none.