A Blue Moon is a phase that traditionally loosens the bonds of magic, on the three days when the Blue Moon rises. It can wreak havoc with all magical forces, causing witches' powers to become erratic and unpredictable or even ineffective. However, the effects of the Blue Moon are only temporary, lasting whilst the blue moon is present.

While some witches may find the ties between themselves and their powers weakened, the Charmed Ones will have an added worry, because not only will the ties between each sister and her powers lessen, but each sister's bond to each other will be weakened as well, thus weakening the Power of Three as a whole, which makes it easier for evil to attempt to destroy it. It is imperative that the Power of Three be guarded on this day.

Influence on the Charmed Ones[]


Piper's anger triggering her power.

On the second Blue Moon of a year (occurring once every fifty years), the Charmed Ones turn into werewolf-like creatures and attack beings of good magic, including Elders and Whitelighters. Aside from the transformation, Piper's temper increased, making her easily angered, resulting in her power of Molecular Combustion blowing up aspects of her surroundings. Meanwhile, Phoebe suffered with emotions of sadness, as her power is passive, she did not demonstrate a lack of control, although she did suffer from violent and painful nightmares (presumably a consequence of her Premonitions). Paige became more susceptible to moments of extreme fright, which caused her to orb out and back again, additionally losing control of orbing objects. All of these adverse effects passed after the last night of the blue moon.

Notes and Trivia[]

  • In "Once in a Blue Moon", it is revealed that every time there are two Blue Moons in a year, the Charmed Ones transform into werewolf-type beasts. According to the show, two blue moons in a year occur every 50 years. Astronomically speaking, there are 3-4 different years each century that will contain two Blue Moons. During these special years, the Blue Moons must take place in January and March.
  • In the past few decades, the definition of a Blue Moon has come to mean two full moons in the same month. Historically, it was the third full moon in a season with four full moons (there are 13 full moons in a lunar cycle). According to the former, a Blue Moon occurs roughly every three years.
  • Additionally, in reality the "Blue Moon" is merely a term, and has nothing to do with the actual color of the moon.
  • It is possible their powers' emotional triggers are what caused their instability: Piper's Molecular Combustion trigger being anger and Paige's trigger being fear. This could also explain why Piper's Molecular Immobilization power didn't malfunction.
    • Even though Phoebe didn't have a known trigger for her Premonition power, it is possible that her excessive sensitivity and sadness came from her connection to her power.
  • The Blue Moon was featured in the non-canonical novel, Sweet Talkin' Demon. During a blue moon, magical bonds are weaker, and the Charmed Ones' bond is easy to break during this time unless all three are close together. A demon named Indar tries to use this knowledge to his advantage and steal the sisters' powers, but he gets outsmarted.

See Also[]