How to Unlock the “The One Free Bullet” Achievement in Half-Life 2: Episode One

This guide will quickly explain how to get the achievement, and what your mistakes may be.

Introduction

This is one of the hardest achievements in the Half-Life franchise. Whether you’re a perfectionist or a collector, this achievement will come in handy for getting the achievement. Note for collectors: somehow this achievement, despite being hard, is more common than lighting up 15 zombies on fire with flares?

Beginning

How to begin the challenge:

• The challenge won’t really start until you get your first weapons in Chapter 3, “Lowlife”
• Once you get the first 2 weapons, you must use your one and only bullet on the lock to progress. You can not avoid the lock unless using cheats, but what’s the fun in that?.
• If you use shotgun on the lock, remember to LMB shoot, as RMB shoots 2 bullets.

After this, there is no need to use a gun to progress in the game.

General Tips

These are the general rules one needs to use to get the achievement:

• You can only use the Supercharged Gravity Gun, Normal Gravity Gun, the Crowbar, the Grenades, Mounted Turrets, Allies, Pulse Balls, and the Rocket Launcher, however remember not to directly hit enemies with Rockets.
• Use the Gravity Gun to throw heavy things, explosives or sharp things. For example: Doors, Grenades, Bricks and Saws.
• You can use the Gravity Gun to adjust the placement of your grenades that you throw, or throw the ones from the enemies back to sender.
• Rockets are a good way to throw accurate projecticles, although the rockets are rare.
• A good way to defend yourself is to get something big, like a door, and block the shots of the enemies (That is, unless the enemies have knockback like the Combine Airship.)
• It is better if you remember to save. It’s obvious why.