"Among other things, Hippiemancy is the magic of relationships: detecting and altering the forces of opposition and attraction which bind people or units. Date-a-mancy is the oddest branch of Hippiemancy, in that it follows the Numbers which underlie all action. Date-a-mancy tries to quantify the intangible, things like leadership and compatibility and morale and Loyalty and Duty and even love, by means of match-ups. This can be very useful in warfare and logistics, but tends to wreak havoc among personal and political relationships. Sides tend not to keep their Date-a-mancers very long, because knowing the cold truth behind our interpersonal relationships only causes grief." (Expository thoughts by Duncan Scone during Book 2 – Text Updates 011)
Hippiemancy is one of the eight major classes of magic in Erfworld. It is the major class defined by the Life and Matter elements together. Hippiemancy can apparently be used to "quiet" a conflict, though the precise meaning of "quiet" has not been revealed.
The performance of Hippiemancy can affect the participants' perception of time, a phenomenon known as "flaking."
A practitioner of Hippiemancy is called a Hippiemancer.
With their confluence of Life and Matter and their absence of Motion Classes, it may be that within Hippiemancy Flower Power (Erf) might influence the environment/nature (space), Signamancy (Fate) might influence perspective/insight (vision), and Date-a-mancy (Numbers) might influence synchronicity (time in meaningful events, or put another way, the inverse of meaningful events in time).