Geomancy is an elemental art of divination more than a thousand years old — sixteen figures born of four simple binary lines, read as a shield of energies around a question. It first appears in North Africa around 900 CE, surfacing in Europe and Greece between 1200 and 1600 CE (Chaucer names it in The Canterbury Tales by 1386). For those centuries it was seen as the sister of, and second only to, Astrology — every university taught it, and people of all walks practiced it, until the end of the 1600s. Later printers dumbed it down to simple tables, and in 1890 the Golden Dawn shrank it further into a parlour trick, yet in the Yoruban Ifá and Arabic Raml it has been practiced continuously.
At its core, geomancy is an elemental art. Every figure is built from four lines — Fire, Air, Water, and Earth, from head to feet — each either active (a single point) or passive (a double point), giving sixteen possible figures, no more and no less. Cast the four Mothers, build the shield of Daughters, Nieces, Witnesses, and the Judge, then read where the figures fall among the twelve houses to see whether and how the matter will come to pass.
Four lines, sixteen figures, one shield — cast, and see what the earth has to say.