Chaotic Era

Chaotic Era is a term from Three Body, the virtual reality game at the center of Liu Cixin's The Three-Body Problem. In the world the game depicts, time is divided between two kinds of period. During a Chaotic Era the sun follows no pattern at all: it may not rise for days, hang huge and scorching overhead, or cross the sky as a small, cold disk, and temperatures swing between deadly heat and deadly cold without warning. The game's inhabitants survive these stretches through dehydration, storing themselves away until gentler conditions arrive. Civilization in the game can develop only during the mild, regular periods called Stable Eras, and no one in that world can predict when one era ends and the next begins. Working out why is the puzzle the game sets its players.