The lunar cycle refers to the phases of the moon as it visibly appears in the sky over time. Beginning with a new moon, in which the moon is not visible, it transitions to the waxing phase, where more and more of the moon is visible as days pass until the full moon is visible. The moon then enters the waning phases, in which the moon is gradually hidden from view until it returns to the new moon phase.
The moon and its phases have a great deal of significance in cultures around the world, as they have inspired a number of myths and legends associated with the lunar cycle. One of the more popular associations is with the concept of the werewolf; humans that transform into monstrous wolf creatures under the light of the full moon.
In Video Games
Some games make use of lunar cycles as a mechanic that affects gameplay, or as a major element of storytelling. Additionally some games with fantasy or science-fiction settings feature dual moons with independent lunar cycles. The combinations of the individual cycles play an important role in the games.
In the world of the Ultima series, there are two moons that operate on independent lunar cycles. The phases of each moon affect special portals found throughout the world called moon gates. The phases of the moons affect where the gates appear, and where they lead.
The Megami Tensei franchise makes frequent use of lunar cycles as a core mechanic that governs demon behavior. In particular, the phase of the moon determines the attitude of demons encountered and how willing they are to negotiate with the player. In Shin Megami Tensei: Nocturne, the moon does not exist, but the same role is filled by the god Kagutsuchi at the core of the Vortex World.
Shin Megami Tensei: Persona 3 uses the lunar cycle to a different effect than previous Persona and Megami Tensei games in general. The game's story is told day-by-day over the course of a school year, and as time passes, the phase of the moon changes. On each night that a full moon occurs, the player is required to enter a special dungeon and face a powerful boss Shadow. Thus, the player must spend time between each full moon preparing for the next.