A recreation room is a room used for a variety of purposes, such as parties, games and other everyday or casual activities. The term recreation room is common in the United States, like the often disappearing room in the Simpsons. The term rumpus room is often common in Australia, New Zealand and Canada. In the United Kingdom, the most common term is games room, or sometimes den. Although, as houses tend to be smaller in the UK, most houses don't have one. Some, however, will have a room specific to one particular game or entertainment unit often found in a recreation room, or some have a snug, which is a smaller cosy room for watching films and playing video games. Often children and teenagers entertain their friends in their home's rec room, which is often located in the basement, away from the main living areas of the house. Usually it is a larger space than a living room, enabling the area to serve multiple purposes and entertain moderately large groups.

In a building or ship, a room is any enclosed space within a number of walls to which entry is possible only via a door or other dividing structure. The entrance connects it to either a passageway, another room, or the outdoors. The space is typically large enough for several people to move about. The size, fixtures, furnishings, and sometimes placement of the room within the building or ship support the activity to be conducted in it.