The warp and the weft are drawn on and manipulated by spellcasters to cast cantrips and spells.

As described by Sara, a Scholar of the Institute of Magic, to Katsu, a Hero of Woodcrest:

“The Weft permeates every plane; it’s always there, just out of reach. That’s what we manipulate to make an effect on the planes. The Warp is the space between the planes; it’s a bubble of sorts, or rather, the boundary of a bubble. You must traverse it, however briefly, to move to other planes.

“Everything is connected by the Warp, and also by the Weft – in a different way.”