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Part 54
Half-Life: Opposing Force

Part 54

A comprehensive guide to defeating Gonarch in Half-Life: Opposing Force, detailing strategies, weaknesses, and item locations for Part 54.

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A comprehensive guide to defeating Gonarch in Half-Life: Opposing Force, detailing strategies, weaknesses, and item locations for Part 54.

Walkthrough
  1. 1
    Locate the cluster of three spiky plants near a large rock wall.
  2. 2
    Hide behind the rock wall to avoid Gonarch's attacks.
  3. 3
    Fire hornets through the gap between the rock wall and plants, aiming slightly below Gonarch's sac to hit it.
  4. 4
    Dodge acid glob attacks by running along the ledge behind the rock wall.
  5. 5
    When Gonarch is damaged, it will break through vines blocking a cave tunnel.
  6. 6
    After clearing baby headcrabs, enter the cave tunnel.
  7. 7
    Find an armor battery and ammo canister near a dead HEV suit soldier. Save your game here.
  8. 8
    Proceed to Section c4a2a: GONARCH COMBAT, STAGE 2.
  9. 9
    Immediately run forward to avoid rockfall.
  10. 10
    Use the Gluon Gun to continuously fire at Gonarch's sac. Adjust aim when Gonarch moves.
  11. 11
    Run forward to dodge acid attacks.
  12. 12
    If Gluon Gun ammo is insufficient, switch to the RPG or assault rifle and use rockets or grenades on the sac.
  13. 13
    If hit, quickrestore and try again. Consider starting with RPG rockets before switching to the Gluon Gun.
  14. 14
    Alternative Strategy (Gauss Gun): Use fully powered altfire blasts from the Gauss Gun. Three blasts should make Gonarch flee. Stay near the cave-in, charge blasts, and hit Gonarch as it approaches. Switch to the hornet gun for baby headcrabs, then return to the Gauss Gun.
  15. 15
    After Gonarch flees, find the large trapezoid-shaped hole in the back corner.
  16. 16
    Drop into the hole and walk to a small stick-out rock.
  17. 17
    Turn around and crouch-walk backward onto the rock, ready to shoot an appearing headcrab with hornets.
  18. 18
    Jump to the rock on the left to avoid more headcrabs.
  19. 19
    Enter the small room past the rock for a healing pool. Refill health to 100.
  20. 20
    Return to the stick-out rock and jump to the remaining rock.
  21. 21
    Quickly kill the headcrab in the next room with hornets.
  22. 22
    Collect the ammo canister and armor batteries.
Tips
  • Gonarch's vulnerable spot is its large, hanging sac.
  • Aim hornets slightly below the sac to ensure they hit it due to their swerving trajectory.
  • The acid attack can be dodged by moving along the ledge behind the rock wall.
  • Save your game before entering Section c4a2a, as it contains one of the game's hardest parts.
  • The Gluon Gun may be sufficient with a full ammo load.
  • If Gonarch hits you with acid or its legs, a quickrestore is often necessary.
  • The SRC note suggests a strategy for the Source version of the game using the hornet gun from a healing pool, but warns of potential invincibility glitches in non-Source versions.
  • Be cautious of headcrabs that spawn after Gonarch flees.

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