Complete walkthrough for Part 18 of Half-Life: Opposing Force, guiding you through the firing chamber, toxic spills, and the Gargantuan encounter.
Walkthrough
- 1After the initial sequence, hit the red "TEST FIRE" button and hide in a corner to avoid rocket damage.
- 2Retrieve the pistol dropped by a guard near the explosives room.
- 3Descend the ladders in the rocket firing chamber to the bottom floor, then find and climb down the ladder in the center pit.
- 4Quicksave, then carefully crouch-walk along the sloped ground until you reach section c1a4g.
- 5After a minor drop, make a major drop into a pool of water. Aim for the center to avoid instant death.
- 6Exit the water and approach the green toxic spill area to find a .357 Magnum and ammo. Find another ammo box on the opposite side of the pool.
- 7Look down into the pool to see two holes. Dive in and go through the right hole.
- 8Move forward and up to emerge on a platform with a ladder. Use the nearby health and HEV stations if needed.
- 9Get onto the large brown pipe to the left of the platform and follow it.
- 10Drop onto lower pipes, move along them, turn right, and drop to a lower pipe.
- 11Run along this pipe until you can jump to a larger pipe with a gap, a valve wheel, and an open hatch.
- 12Use the valve wheel to close the pipe gap.
- 13Crouch-drop onto the ladder near the open hatch and climb down to avoid health loss.
- 14Jump over the large hole in the pipe segment, then crouch-walk through a small fencing hole.
- 15Continue down the pipe until section c1a4j loads.
- 16In section c1a4j, turn the last corner to a large discolored pipe segment. Walk onto it to break and slide down. Lean on the "Move backward" key to reduce fall damage.
- 17If you don't land on the table, jump onto it to crush the headcrab, get .357 ammo, and potentially health.
- 18Bash crates to find health packs and five unset tripmines.
- 19Move down the corridor past the room to reach the start of the "Power Up" chapter.
- 20Section c2a1: Gargantuan Problem
- 21Optional Skip (Non-Source Version): Run into the gargantuan's chamber, then through the large opening on the right. If you reach the concrete barricade fast enough, the gargantua won't follow. Use two laser tripmines to create a path over the barricade. Set the first tripmine on the middle of the three lower concrete sections, jump on it, move right, set the second tripmine on the upper middle section, and use it to jump over.
- 22Standard Progression: Enter the chamber where a gargantua fights two marines. Run to the doorway directly across from your entry point.
- 23As soon as you're through that doorway, equip the shotgun and look down the hallway to the right.
- 24Shoot an explosive barrel when a vortigaunt appears to kill it.
- 25Pass the vort's side hallway and continue down the main one.
- 26Reach a broken floor with a pipe shooting flames. Quicksave.
- 27Move past the pipe to where a vortigaunt sees you, then back up quickly around the corner. The vort should kill itself on the flames. If not, quickrestore and try again.
- 28After flaming the first vort, quicksave and repeat the process for the second vortigaunt.
- 29Crouch-walk to the floor hole the pipe is sticking out of. Use the pistol to kill the four headcrabs on the floor below, watching out for the pipe's flame.
- 30Around the corner past the pipe, go up to the railing and shoot the two…
Tips
- Hiding in a corner near the "TEST FIRE" button is crucial to avoid rocket damage.
- The drop into the pool of water requires precise aiming to avoid instant death.
- Using the "Move backward" key while sliding down the collapsing pipe can mitigate fall damage.
- Tripmines are very useful for both bypassing the Gargantuan encounter and for general combat.
- Exploiting environmental hazards like flames and explosive barrels can make combat encounters easier.
- .357 Magnum
- .357 Magnum Ammo
- Health Packs
- HEV Station access
- First Aid Stations access
- Five unset Tripmines
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