|This article is written
from the Real Life
point of view
Room States are what determines what is in a room at what time in a Metroid game. Most rooms have only one room state, but many have two, three, or even four room states. Different room states are triggered by certain events occurring within the game. This can range from collecting an item to defeating a boss.
Room States determine which areas are accessible at what times, and change throughout the game. Some of the changes are aesthetic, such as the rainfall ceasing in the Landing Site of Crateria after the acquisition of Power Bombs, while some are very important, such as the destruction of Sector 5 after acquiring the Plasma Beam. Changes in Room States are generally irreversible, but are usually for the better, with one exception being Dark Pirate Commandos appearing throughout Aether after the acquisition of the Grapple Beam, because they can be a nuisance to the player when they are exploring.