others make them allies. There are fifteen factions in total. The Faction War In 1998, TSR published Faction War, an adventure that effectively closed the book on Planescape, as it was then ending the product line. The culmination of several adventures leading up to that point, the Faction War brought an end to the factions' control of the city. Instigated by the power-hungry Duke Rowan Darkwood, factol of the Fated, in a bid to dethrone the Lady and rule Sigil himself, the war spread throughout the city before the Lady of Pain, with the aid of a group of adventurers (the players' characters), intervened. Sects Sects are in many ways identical to the Factions, differing in that they are not based in Sigil. Sects are often highly specific to the particular planes they originate from, though historically many of the Factions were once Sects and some Sects were once Factions. Rules There are three principles (or heuristics) governing the world of Planescape: the Rule-of-Three, the Unity of Rings, and the Center of the Multiverse. Rule-of-Three The first principle, the Rule-of-Three, says simply that things tend to happen in threes. The principles which govern the planes are themselves subject to this rule. Unity of Rings The second principle is the Unity of Rings, and notes that many things on the planes are circular, coming back around to where they started. This is true geographically as well as philosophically. Center of All The third principle (fitting neatly into the Rule-of-Three above) is the Center of All, and states that there is a center of everything—or, rather, wherever a person happens to be is the center of the multiverse... From their own perspective, at least. As most planes are functionally infinite, disproving anyone's centricity would be impossible. In Planescape, this is meant philosophically just as much as it is meant in terms of multiversal geography. The fact that anywhere could be the center of the multiverse in this view also implies that nowhere can be said to be the only absolute true center. This sparks a lot of arguments and violence since some people believe the City of Doors to be the center due to its uncommon number of portals to other planes and position in the Outlands and some factions also claim different centers, each with their own significance. Official products Boxed sets 2600 Planescape Campaign Setting 2603 Planes of Chaos 2607