Gas explosion

Ignited explosive gases.

Explosive gases are commonly encountered in underground locations and buildings, such as Warrington Trainyard and Our Lady of Hope Hospital. They have also been encountered in a few outside locations, usually near ovens or gas lines.

How to spot the gasesEdit

  • The air will start to distort as you stand still and see through the gases.
  • When you fire a weapon that is a source of ignition (flamer, energy weapons, etc.) the immediate area will ignite in flames.
  • The source is a pipe that has been broken/cut, which can be found by extensive search.


  • The gas ignites when any ignition source is triggered within it. The following will ignite gas:
    • The projectile or beam of any Energy Weapon included in the vanilla game (those from add-ons do not appear to have the same effect).
    • The firing of any bullet-based weapon; the point of ignition will be the weapon itself. Flying bullets will not trigger the gas, but the impact of bullets from the Zhu-Rong v418 Chinese pistol create gas-igniting flame.
    • Any explosive or explosion.
    • The presence of any open-flame weapon (Shishkebab, flamer, heavy incinerator): presence meaning it is active and in someone's hand.
  • Use caution when igniting the gases as it can cause damage to you, and knock you down, if you are too close.
  • This can also be used as a weapon, since your enemies and all other characters will experience the same effects.
  • This is a trap and is meant to harm/kill creatures and humans. It is used by Horace Pinkerton and Reilly's Rangers for this.
  • Bio-gas canisters are used by the player to create explosive gas. They can only be found with the Point Lookout add-on.


Explosive gases appears in Fallout 3 and Fallout: New Vegas and Fallout 4.

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