Sphere
A sphere (Japanese: タマ tama) is the basic unit of currency in the Underground of Sinnoh. They come in five colors: Red, Green, Blue, Prism, and Pale. These correspond to different versions of the Pokémon games, with the first three matching the original colors of Red, Green and Blue, and the Prism and Pale spheres corresponding to Diamond and Pearl respectively.
Spheres of these five colors can be found commonly by mining in the Underground. More common are those that are Red, Blue, and Green, while the Pale and Prism spheres are quite rare. Spheres can range in size from 1 to 99, though most spheres found will be in the range of 5-20.
To get larger spheres, they must be either combined by burying more than one of the same color sphere in the same spot, or left to grow after burial. When combined, the size of the resulting sphere is determined by the formula a² + b² = c², where a and b are the size of the spheres being buried and c is the size of the new sphere. It is currently unknown at what rate spheres grow while buried, but Red, Green, and Blue spheres grow at a faster rate than Prism and Pale spheres. Spheres max out at 99, no matter what is added to them.
Spheres can be used to purchase many things that a player will need to decorate their secret base, as well as traps which can be set up throughout the underground. Hikers that stand at some of the corners of the Underground will offer to trade these items for the spheres. The price that the item is listed for is the minimum size sphere that the hiker will take for it, though larger ones may be used.
