Fortune-telling

Fortune-telling is a form of superstition. Its roots can be traced back to ancient times. In Delphi, an ancient sanctuary in Greece, there were priestesses/oracles called Pythias. Nostradamus was a famous French prophet from the Renaissance period. A common theme in the predictions of the Pythias and Nostradamus (and any other "prophet" or fortune-teller for that matter) is that their prophecies were told in a vague, often self-fulfilling way, without a specific date in mind.

Fortune telling can also be when a supposed psychic reads your palm, makes a chart for astrology, or "channels" spirits of the dead for answers.

If a psychic tells your future through the use of the supernatural, this is called divination. Divination is extremely popular in various circles, including Neopagans who tend to use traditional arcane methods that rely somewhat on chance.

Christians officially frown on fortune-telling or divination, but some people (like Harold Camping) engage in it anyway by claiming that God has told them the world is going to end or a major disaster is coming.

There have been many other methods of trying to predict the future in the past, but animal sacrifice is frowned upon now.

Fortune telling doesn't always work — as shown here.

Bujo / Egg curse scam
Some unscrupulous fortune tellers use the divination business as a front for a scam traditionally called the bujo or egg curse scam. The fortune teller uses her cold reading skill to detect that a client is genuinely troubled rather than merely seeking entertainment; or is a gambler complaining of bad luck. The fortune teller informs the mark that they are the victim of a curse, but that for a fee a spell can be cast to remove the curse. In Romany, this trick is called bujo, originally meaning simply "bag", but now meaning "a swindle involving a large amount of money from a gullible fortune-telling customer."

This name comes from a traditional form: the mark is told that the curse is in their money; they bring money in a bag to have the spell cast over it, and leave with a bag of worthless paper; or money or property are given to the fortune teller to be destroyed as bearing the curse, and an item of lesser value is swapped and conspicuously destroyed instead. In some cases the curse is "verified" by a sleight of hand trick, often involving an egg. The fortune teller tells the mark to bring an egg to a reading, which when cracked open reveals disgusting matter or symbols of evil. This discovery confirms the curse.

Tasseography
It's only tea leaves—stop being dramatic! Tasseography (tasseomancy, tassology) is the posh word for a group of divination/fortune-telling methods that involve "reading" patterns in coffee grounds, tea leaves or wine sediments left in a cup after emptying it. The usual name is 'tea leaf reading', because tea is the customary medium used.

For best results, tea must be brewed in a teapot without a strainer, because getting tea leaves into the cup is the object. A wide, cylindrical cup allows for the patterns to form. The person consulting this oracle must drink most of the tea, leaving some in the bottom to swish around three times. This creates the patterns in the wet tea leaves that are read by the psychic interpreting the oracle. Letters, numbers, and various imagined symbols in the patterns of the leaves whose meanings are more or less obvious (an angel means good news, an airplane foretells travel, etc.) are then discerned in the wet leaves.

It is a fairly benign example of a far larger class of methods of divination which involve looking for suggestive patterns in an apparently random arrangement of matter. Similar methods include the Roman custom of haruspicy (or extispicy) whose practitioners examined the entrails of animals; pyromancy where shapes in fire suggest hidden messages; ceromancy using patterns formed from dripping wax; molybdomancy with molten metal; nephelomancy by looking at clouds; scrying with a reflective surface; and according to one Wikipedia editor, "Ureamancy: by gazing upon the foamy froth of urine created within water."

Like other types of fortune-telling, when it "works", it "works" mostly by cold reading (or hot reading, if the fortune-teller is unscrupulous enough and the stakes are high enough). Potentially, as with the Rorschach inkblot test, it may also reveal something about the mind or subconscious of the reader.

Chiromancy
Palmistry or palm-reading is a bunch of crap that claims to be able to tell a person's future based on the lines on the palm of their hand. It has its roots in ancient Hindu astrology: a textbook called Teachings of Valmiki Maharshi on Male Palmistry is attributed to the epic poet Valmiki (active sometime between 500 BCE and 100 BCE). In classical Greece, Anaxagoras and Aristotle both discussed it; the latter's Historia animalium suggests the lines on the palm predict the length of life. However it was less acceptable to Christian authorities (although is sometimes said to justify palmistry, saying God "sealeth up the hand of every man; that all men may know his work.") Despite church suspicion, it never entirely went away, and enjoyed a certain popularity in the Renaissance, apparently as a result of social turmoil and relaxing church controls, with the development of printing allowing maps of the hand to be distributed.

Palmistry was repopularised in the 19th century by improbably-named figures such as Captain Casimir Stanislas D'Arpentigny, Katharine St. Hill, Edgar de Valcourt-Vermont (Comte de St Germain), William John Warner (who called himself Cheiro and had numerous celebrity clients including Mark Twain and Gladstone), and Edward Heron-Allen (a polymath who also translated the Rubaiyat of Omar Khayyam and wrote extensively on asparagus).

The usual method involves studying the appearance of lines and bumps on the palm, which are given colourful names such as the heart line, head line, simian crease, Girdle of Venus, sun line and earth line. Different parts of the palm are associated with heavenly bodies that also feature in astrology, and hand types are compared to the four elements of the now-discredited ancient Greek classification (earth, air, water, fire). Palmists consider factors such as the length of lines, their presence or absence, whether they meet, how broad or gridded they are, the relative sizes of different features, etc. Its popularity may be explained by it involving minimal raw materials and less math than astrology; it can be done anywhere; and you get to hold people's hands.

It is generally accepted as fraudulent, considering one of the "methods" is to make stuff up. Strangely, some people believe in it. They're probably the same people who read their stars in the paper or go to fairground fortune-tellers for "genuine" advice.

Astrology
From personalised star charts to newspaper horoscopes, it's all bollocks.

Bibliomancy
Predicting the future by opening a book at random and seeing what is there; a particular line or word is often chosen at random (e.g. by pointing with the eyes closed). Sometimes a holy or revered book is used such as the Bible or Quran, but other texts can be used, and one variant involves first selecting a book at random. It actually works quite well if you've been looking at a particular page in a travel book and bent or broken the spine. The poet Robert Browning was an acolyte and consulted Cerutti's Italian Grammar to find out if he should marry Elizabeth Barrett Browning. The practice is also known as stichomancy and very similar is rhapsodomancy, which uses a random passage from a poem. Divination using the I Ching involves selecting a passage at random from the I Ching.

Other techniques

 * Channeling &mdash; possession by "spirits"
 * Tarot cards
 * I Ching
 * Scrying &mdash; with a crystal ball or other reflective surface
 * Runes &mdash; by some neo-pagans
 * Molybdomancy
 * Machines that cost $.25 at a carnival, most famously Zoltar/Zoltan
 * Fortune cookie
 * &mdash; common in Brazil by followers of and
 * etc.
 * etc.
 * etc.