Small World: Realms includes dozens of puzzle-like geomorphic terrain regions that are assembled into board maps of various sizes and shapes. The map designs are based on any of the 12 preset scenarios created by the game's designer, Philippe Keyaerts. Players can also create their own maps and scenarios using the included components.
Small World: Realms can be used with any of the base games of the series: Small World or Small World Underground. For this, the pieces have two sides, one for the base game and another for the subway version.