Kabbalah

Kabbalah is a form of Jewish mysticism that either takes shape in 13th-century Spain with a group of Jewish mystics, or during the Exodus while Moses was talking to God if you are a Jewish mystic. Different Jewish denominations have different stances towards Kabbalah. More modern denominations, such as Reform and Conservative Judaism, think Kabbalah itself is nonsense but the academic study of Kabbalah is valid scholarship. Chassidic Judaism, on the other hand, takes Kabbalah pretty seriously, and Orthodox Judaism has views in both camps. It has reached wide popularity via a shiny, Power-of-Positive-Thinking version that Madonna has been wearing since about 1997, but this is only one of the dozens of movements trying to claim the word as their own. Books about Kabbalah tend to have less in common with one another than books about cooking do.

The word means "The Tradition" in Hebrew, and it usually means "The Secret Traditional Explanation of Everything," so it has been fights and collaborations between rivals since the beginning. Who wouldn't want to fight over that? The version of the Kabbalah that got big in the 13th-century Spain was deeply entrenched in the Jewish religion and tended to deal with the questions that bothered 13th-century Jews, such as "Why are we following these Laws?", "How did the Universe come about?", and "What's with all these contradictions in the Bible?" They weren't new questions, but kabbalists found some new ways of asking them, usually by looking for hidden messages in the Torah using MATHS, reading Hebrew words as numbers, and numbers as the stuff the universe is made of. Particulars were debated, but the hidden message tended to be that the Universe is made of parts that are out of harmony, but if all Jews were to follow Jewish Law, the universe would be fixed. The Zohar and the writings of Abulafia are the classic from this period, the first being more like sacred adventure stories, and the second being training manuals for prophets. They both claimed to have the ancient secrets, but they disagreed on most specifics.

And since then people have continued claiming that their newly discovered version of the ancient tradition is truer than all of the other newly discovered versions. In the Renaissance, Christians discover that the secrets were actually Christian secrets, and Masons later discover that those Christian secrets were also Egyptian or Babylonian secrets. People like Aleister Crowley discovered that these Masonic secrets had always been magical secrets, or that they explained everything from Taoism to Quantum Physics. From the Jewish side, the "Ari" (an akronym meaning "Lion") Isaac Luria discovers some details about how our universe is on top of a shattered previous one, in the sixteenth century. Hasidism makes it folksy, dancey, and dynastic in the eighteenth century. The popular new ones are strange, but it would be hard to show that they were stranger than the ones that were new before.

The Kabbalah is also known for the snazzy tree pattern known as the Tree Of Life, whose leaves are the Ten Sephirot, connected by 22 paths (each associated with one letter of the Hebrew alphabet). These ten spheres are connected in a pattern that shows how God emanates into our level of reality.

References to Kabbalah in fiction include:

Anime and Manga

666 Satan: The Kabbalah is shown throughout the series as a sort of sandwich on the earth.
In Fullmetal Alchemist, the Tree of Life is one of the mystical symbols appearing on the mysterious Gate.
Neon Genesis Evangelion loves its Kabbalistic symbolism. Now, whether it means anything...
- The entire tree is lovingly drawn on Gendo Ikari's office floor, and considering how hip deep he is in reenacting key parts of the original story to bring back his wife and initiate Third Impact, it may have somewhat more meaning, insofar as he and SEELE are concerned.
In Psyren, Amagai Miroku's Sephirot attack is based on the Tree of Life.
Digimon Frontier references it a couple of times. First is Mercuremon's evolved form of Sephirotmon, which is actually composed of orbs in the same pattern as the Tree of Life (complete with the Crest of Light from Digimon Adventure on the central orb). Ophanimon has an attack called Sephirot Crystals, in which she summons crystals in the same Tree of Life pattern as well.

Comic Books

Alan Moore's Promethea series is strongly oriented by the Occult Kabbalah of Aleister Crowley and the sex magick tradition that has been riffing on him (whether or not he liked it then, or his devout like it now) for the last century. A trip through the Tree of Sefirot fills up all of books 3 and 4.
Ben Katchor's The Jew of New York includes Kabbalistic meditation on the word "Greptz", a Yiddish onomatopoeia for a burp sound.

Fan Works

The RWBY/The Gamer crossover fic The Games We Play uses the emanations of the Sephiroth as the basis for the Anatomy of the Soul in the setting, something that turns out to be critical to the long-term plot.

Film

Pi has explicit references to Gematria, the kabbalistic practice of analyzing Hebrew words as numbers.

Literature

Bee Season, both the great book by Myla Goldberg, and the mediocre movie with Richard Gere, has Abraham Abulafia's prophetic techniques, Isaac Luria's idea of fixing the world, and Hasidic dancing. Of course, this is in a family with serious problems, so these get translated into obsessive compulsion and Hare Krishna.
Illuminatus!‍'‍s chapter names are named for sephirot. So has Umberto Eco's Foucault's Pendulum.
Gustav Meyrink‍'‍s Golem is heavily influenced by Kabbalah (and by antisemitism). Not very surprisingly so, seeing as the Golem legend is itself heavily kabbalistic, and Meyrink was deeply involved with the esotericism of his time.

Tabletop Games

GURPS Cabal is a game setting in which kabbalah is as ancient as the Jewish mystics claim. Kabbalism is one of the very few "real" (in that universe) paths to potent magic, and Qliphoth are extremely dangerous beings.
Kabbalah: Mythic Judaism was a 1998 supplement for Ars Magica quantifying Jewish mysticism and magic for use in the game.

Video Games

Both Hellgate:London and Clive Barker's Jericho have heroes who are techno kabbalists.
Trickster Online takes place on Kabbalah Island and includes all sorts of specific references to Sefirot.
Final Fantasy VII's Sephiroth takes the name from the Tree of Life. But that seems to be it.
The back wall of the bathroom where you start the game in Silent Hill 2 has kabbalistic drawings on it.
The occult-obsessed school nurse in Persona 3 will lecture the main character about Kabbalah and various derivative practices.
Tales of the Abyss derives much of its mythology from Kabbalah, instead of the series' habit of drawing on Norse Mythology. Sephiroth are Auldrant's ten major magical 'hotspots', the Qliphoth is a lifeless underground sea of hot mud and poisonous gas, and several towns in Malkuth take their names from the actual Sephirot. Malkuth itself is named for the lowest Sephirot, which means 'kingdom'.