A congregation gathers at an ounfo, a temple compound, whose main space is the peristil, a roofed area centred on the poto mitan, the post down which the lwa are said to descend. Around it are altar rooms holding the objects, images and food of particular spirits. Ceremonies are nocturnal, long and driven by drums; each lwa has its own rhythms and songs, and the drummers are as necessary to the rite as the priest.
Leadership belongs to the oungan, a priest, or the manbo, a priestess, and the two roles are equal. Both take charge through initiation, a graded process culminating in receiving the ason, the beaded rattle that marks priestly authority. Initiation is costly, secret in its details, and understood as the acquisition of konesans, knowledge, rather than as ordination to an office. Many people who serve the lwa never initiate at all: they inherit obligations, consult a priest when needed, and keep small household altars. There is no central authority, no scripture and no body that could rule on doctrine, so practice varies from region to region and house to house.
Ancestors matter as much as the lwa. A family's dead are fed and consulted, and the Gede who govern death are treated with a bawdy humour that visitors often find startling. Ginen, Africa understood as an ancestral homeland beneath the waters, is where the lwa and the dead are said to reside.
Most people who serve the lwa are also baptised Catholics and see no contradiction; a Haitian proverb holds that one must be a good Catholic to serve the spirits. That overlap makes counting impossible. Estimates that half or more of Haitians participate in some form are common, but no census asks a question capable of capturing it, and rapid Protestant growth has produced a large body of Haitians who explicitly reject the tradition.