The new Call of Duty: Warzone Durable Gas Mask, or gold gas mask, seems to spawn exclusively in the secret Stadium rooms. For the uninitiated, there are keycards in Stadium that players can get to access locked rooms in the building. These rooms have some high-tier loot, not unlike the bunkers that are found elsewhere on the battle royale map. It’s entirely possible that the Warzone Durable Gas Mask spawns in other bunkers or just out in the world as well, but most reports seem to indicate that they are exclusive to Stadium.

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In any case, the Durable Gas Mask functions like one might think. It’s essentially just a much stronger and longer-lasting version of the regular gas mask. This means that Call of Duty: Warzone players with a Durable Gas Mask can stay in the poison gas a lot longer than other players, in turn giving them a pretty big advantage near the end of any given match.

So far, the Call of Duty: Warzone Durable Gas Masks seem to be pretty rare, so they shouldn’t shake up the meta too much. The downside to them is that they still have the gas mask animation that some Warzone players have complained about, as it can ruin their chances in a firefight as the gas closes in on the final circle.

There are many other Warzone Season 5 secret changes that weren’t mentioned in the patch notes. For example, Infinity Ward quietly changed the prices of some of the items at the Warzone Buy Stations, making Self-Revives and team buybacks $500 cheaper than they were in Season 4. Infinity Ward also changed up the weapons that players can use in the Gulag, as well as added some new architecture to Prison.

Perhaps the biggest secret change to Warzone was the introduction of the Stadium access code easter egg, though that has now been solved by the community. By figuring out the Stadium access code and getting to hidden rooms in Stadium, Warzone players can get their hands on high-tier loot as well as trigger a special fireworks event. It’s not the Black Ops Cold War tease that some fans were expecting, but it’s still a neat easter egg nevertheless.

Call of Duty: Warzone is out now for PC, PS4, and Xbox One.

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