A magic circle (魔法陣 Mahoujin) is a figure composed by a great number of symbols related to the powers, techniques and procedence of the magician. Generally, the magic circles are what differentiates mages from one another, each creates a magic circle of their own - it is like their signature. Magic circles work as an field of energy that activates the moment a mage is about to perform a spell. This magic circle is visible under the mage's feet, and its power surrounds him/her as if it was a Ki or Aura.
Clow Reed's Magic Circle
The figure for Clow's magic circle consists of a 12 point-star, with the symbols of the cardinal points inside the corners. It has the image of the Sun in the centre, and next to it is the Moon. Clow's magic is symbolized by "Light and Darkness", his guardians are Kerberos (Sun) and Yue (Moon).
Clow's magic is also a mixture of both Western and Eastern magic (having an English father and a Chinese mother), so it also has both Chinese and English characters on it.
- This magic circle is the same used for Fei Wong Reed (Ch. 183), Xing Huo, and Syaoran Li and Watanuki (Ch. 213).
High Priest Yukito's Magic Circle
High Priest Yukito uses a magic circle based on Clow Reed's, as he was taught by Clow Reed himself, but instead of a Sun symbol, it has a second, bigger crescent Moon symbol at the middle, referring to his moon-based powers. It has the same runes, but are sharper and more refined than the stylized symbols in Clow Reed's circle. It also appears to have the spokes of a solar symbol beneath the larger moon, possibly representing a solar eclipse. It is also worth mentioning that like Clow Reed's circle, it has text within it and if looked at closely, the words "magic square" could be made out repeatedly. It can be assumed that the text within Clow Reed's circle is the same.
Sakura Kinomoto's Magic Circle
The main symbol in Sakura's magic circle is the Star within it. Like Clow's, it forms a 12-point star with three squares, surrounding these are the symbols of the Western Zodiac. Next to the 10-point star in the center is the Sun and the Moon. These represent Yue and Kerberos who protect the star, meaning Sakura.
The Chinese written on this circle signifies the cardinal direction points on a compass.
北 (Běi) is located on the top and means "North"
東 (Dōng) is on the right and means "East"
南 (Nán) is located in the bottom and means "South"
西 (Xi) is towards the left and means "West"
The Western Zodiac symbols in the inner ring of the cirles are as followed from the top left going clockwise: Leo, Virgo, Libra, Scorpio, Aquarius, Pisces, Aries, Taurus.
During the final confrontation with Eriol, Cerberus and Yue’s powers are combined into Sakura's staff. This once more transforms her staff into a final bigger version although the magic circle stays the same. Sakura’s magic is drawn from the power of the stars, which may start small, but are ever-shining with their own brilliant light.
- This circle is the same used for Sakura Li, maybe due to the fact that she recieved the Star Sealing Wand from Sakura Kinomoto.
Syaoran Li's Magic Circle (Cardcaptor Sakura)
Although not a magic circle, the compass' outline is also seen for Tsubasa Li.
Syaoran Li and Tsubasa Li both use the same magic compass and sword. In the 1st Cardcaptor Sakura movie, Yelan Li, Syaoran’s mother uses the same magic compass as well.
From the characters closest to the yin-yang symbol and going around clockwise, they read:
冬、春、夏、秋 - winter, spring, summer, fall
水、火、風、地 - water, fire, wind, earth
北、東、南、西 - North, East, South, West
天、鬼、地、神 - Heaven, Demon, Earth, God
Yūko Ichihara's Magic Circle
The main symbol for her magic circle is one circle in the center, within it is an eye, and surrounding it are the phases of the moon. This circle is interconnected to 8 more, from which 4 of them are bigger than the other 4.
The little circles contain: the avatars of the mashin in Magic Knight Rayearth. Three of the symbols in the diagonals of the circle are the Rayearth "machine" symbols. The fourth diagonal looks to represent the symbol for infinity.
In the external circle are the symbols of the Western Zodiac.
- Yūko's circle is also used for Sakura Li.