Numen points are aquired by sacrificing items via a Ancestral Shrine.
Prayers[]
You get a new Prayer menu when you get enough numen for a prayer.
Light of the Ancestors, 3NP: Light effect on your character determined in strength by the perception + exploration of your ancestors. The effect lasts six ingame hours.
A Prayer for Bread, 5NP: You get a loaf of bread, quality determined by the cooking skill and the perception values of your ancestors.
Prayer of a Lost Child, 10NP: You get a local map of the area you are in, filled in to a degree corresponding to the perception/exploration values of the ancestors.
Forge Prayer, 10NP: gives you a metal nugget, chosen at random from Cast Iron, Tin or Copper, at a quality that is the same as the amount of Numen points available to the character, but soft-capped by the ancestor's Strength and Smithing levels. [2]
Prayer of Life, 20NP: will take a seed (any seed) in your inventory, and change its quality to that of your ancestors' Farming stat (not softcapped). [3]
Einherjeraspekt, 40NP: Strength, melee, unarmed and ranged combat values of your ancestors are added to yours. This effect lasts for one full ingame day.