Lethal gas is found in many forms and in many environments. It is naturally found in many underground settings (in Real Life as well as in games, particularly near volcanoes) and is abundant in the atmosphere of many planets. Humans have used it as a weapon of war, a method of execution, and in certain historical mass death traps. In video games, being surrounded by poisonous gas is likely to deplete your Oxygen Meter very rapidly. Sister trope of Knockout Gas, the non-lethal alternative. Not to be confused with Fartillery. Examples of Deadly Gas include: