The Moon Phase System or lunar phase (月齢, getsurei)? is a component of a vast majority of Megami Tensei games. The various phases of the moon often affect battle, negotiation and fusion, and often affects other aspects of the game as well. The moon phase often functions as a counter for item and spell effects, such as a spell lasting until the next new moon. Regardless of what variation the system takes, the cycle of the moon phase is always as follows:

First quarter Last quarter
Waxing crescent Waxing gibbous Waning gibbous Waning crescent



In most offline installments, the phase changes depending on how many steps the player has moved the character in the dungeon or large map, if movement is not menu-based. Moon phase changes automatically following the in-game clock in Shin Megami Tensei NINE and Shin Megami Tensei IMAGINE. In Persona 3, it simply follows the real world calendar and the phase changes day by day.



Shin Megami Tensei IIEdit

Demons will gain or lose power depending on the phase of the moon and their specific moon affinity type, based on the following chart, where "8" is half damage, "16" is normal damage and "32" is double damage:

Type New1/82/83/8Half5/86/87/8Full

The moon phase affects demons' power in Shin Megami Tensei and Shin Megami Tensei: if... as well, however charts for how moon phases affect each phase affinity type are unavailable at this time.

Shin Megami Tensei IMAGINEEdit

While moon phases do not have any effect on negotiation or fusion, they do change various elements of the in-game world. Shops will change their merchandise at certain moon phases, offering unique cards, weapons, compendium memories and consumables.

During the New Moon period, Inviolable variations of Divine demons will spawn in Shinagawa. Killing a large number of them will spawn a Dominion field boss. This period also changes two of the Shinagawa-based dungeons to feature a large amount of Haunt demons and a different boss entirely. Hresvelgr is replaced by Nidhoggr. Norn is replaced by Nyx. A field boss variant of Daisoujou can also be spawned by law alignment players in Kuchinawa Caverns.

During the Full Moon period, synthesis success rate and cultivation expertise gain are increased. It is also possible to fight the field boss Nyarlathotep during this period.

Shin Megami Tensei IV ApocalypseEdit

The Moon Phase changes as the story progresses, eventually reaching a Full and Misoka Moon at its climax on the Peace/Anarchy routes. It is merely cosmetic and does not affect game mechanics in any way.

Megami Ibunroku PersonaEdit

Moon phases do not affect demon conversation, and seem to serve little purpose except that Unknown Powers can only be obtained by fusing Personas under specific moon phases, primarily the New Moon.

Persona 3Edit

The moon phases play similar roles as in other Megaten games, except that the moon phase is determined by days of the month as opposed to footsteps. Every time the full moon appears, it signals the appearance of a strong Shadow.

Certain abilities receive a damage boost during certain moon phases.

Digital Devil Saga: Avatar Tuner 2Edit

The team has a chance of entering Berserk Mode during 7/8 or 8/8 phases, although there is a piece of equipment, the Berserk Ring, which allows the team to enter Berserk Mode regardless of solar phase except for compulsory battles.


Shin Megami Tensei III: NocturneEdit

The moon no longer exists. Instead, the phases of Kagutsuchi play almost the same role the moon did before. Full Kagutsuchi results in maddened, crazed demons which do not think rationally. New Kagutsuchi results in quiet, subdued demons. Several fusion results are dependent on Kagutsuchi's phase, and the game's unique sacrificial fusion system requires a Full Kagutsuchi phase. There are also conversation skills that involve the Kagutsuchi phases to improve enemy responses.

Several puzzles and locations in the game require the use of the Kagutsuchi phase, as well.

Shin Megami Tensei: Strange JourneyEdit

The Schwarzwelt's moon serves as the Moon Phase System. Fusions are more likely to fail in full moons, demons act irrationally and relax their inhibitions allowing for recruitment of demons of the dark alignment if the SubApp Lunatic is installed, and certain attacks work better on certain phases.

  • In Horologium, a specific teleportation point will only work properly if the moon is full.

Persona 4Edit

Weather takes the place of the moon phases, with different weather creating a different effect. Important events will occur during foggy days. The effects of the moon phase on fusion are effectively replaced by the Fusion Forecast system.

Digital Devil Saga: Avatar TunerEdit

The moon phases are replaced with the "Solar Noise", which has the same basic function as the moon phases. If any of the characters have a status ailment such as silence or poison and the solar noise is minimum, those status will be healed. Cells will be sold at a maximum price at Maximum Solar Noise and will be sold at their lowest at Minimum Solar Noise, with the single exception of the Jack Cell, which is exactly the opposite.

Community content is available under CC-BY-SA unless otherwise noted.