I am still forming the concept of this campaign in my head, but this is what I have so far. Constructive criticism welcomed.
Dimension Lords
Every dimension exists as a point in space of the Polyverse. Time within each dimension exists as a line in space. There are a finite number of these points, although, they are so numerous as to be nearly impossible to count. Every new thought an individual has in one of these dimensions, creates a new dimension where that thought becomes a reality. No one knows if there is limited space within the Polyverse so that new thoughts would stop creating new dimensions nor what would happen if this occurred.
The laws of physics are not universal and may change from dimension to dimension. However, there are laws that are universal. These are known as the Noble Truths. These are concepts such as Compassion, Justice, Honor. Each of these is ruled over by a king or queen who attempts to expand their realm's influence throughout the Polyverse. For each Noble Truth, there is its opposite, also ruled over by a king or queen. These rulers battle one another through their subjects throughout the Polyverse.
The PCs serve the Duke of Generosity who serves the Queen of Compassion. Their arch-enemy is the Arch-Duke of Indifference.