Carapacians are a species in Homestuck that resemble anthropomorphic chess pieces, residing in pocket universes known as Incipispheres. They are divided into two different races which war over Skaia, attempting to either protect or destroy it. The Prospitians, who resemble white chess pieces, strive to protect Skaia, while the Dersites, who resemble black chess pieces, strive to destroy it. They are locked in eternal stalemate until a group of individuals begins to play Sburb and bring their prototyped kernelsprites into the Incipisphere causing the Battlefield to increase in complexity, thus breaking the stalemate, while modifying the form and abilities of the royalty to match the prototypings.
Over the course of the war, the Black King defeats the White King and triggers an event known as the Reckoning which wipes out the species of the individuals playing Sburb, this also allows, through various circumstances, carapacians to be exiled from the Incipisphere to the players' home planet where they rebuild civilization.