Discontinuity Points are measurable, definable, tangible astrophysical positions in deep space, and detectable to those trained in their use.

Travel between Spheres is only practical through the use of Discontinuity Points. Without using Discontinuity Points a Spellship travelling at maximum velocity (100,000,000 miles /day) would need almost 644 years to traverse the 4 light years (or 23,514,501,486,269 miles) that separate Arvandor from Nexhan, its closest neighbour.

Discontinuity travel between Spheres can only take place at locations where Discontinuity Points exist.

The generalized locations of Discontinuity Points are approximately fixed in space, but are subject to slight fluctuations in position, usually amounting to no more than 3 AUs, or 300 million miles. (One Dominion AU has been standardized as the average distance from Arvandor to its sun, a distance of 100 million miles.)

Cosmologically, the same forces that created stars also created the Discontinuity Points. Thus, no Discontinuity Points exist in the absence of stars.

Although not proven, there seems to be a correlation between the density of Discontinuity Points and the size of the nearest star (including those within Crystal Spheres). The larger the star, the less dense the number of Discontinuity Points around it.

No Discontinuity Point can exist inside a Crystal Sphere.

Known Discontinuity Points only connect to other Discontinuity Points. They connect to nothing else--or if they do, the Spellships taken there haven’t returned to tell about it.

A Discontinuity Point may connect to more than one other Discontinuity Point. They are then called Polydiscontinuity Points and have a minimum of two portals plus the point of ingress. Current scholarship suggests that there is no limit to the maximum number of portals they can have. The destination, or egress point, of a Spellship that enters one of these Polydiscontinuity Points depends on the speed, course and vector at which it enters the portal. A highly skilled navigator, helmsman and crew are of the utmost criticality to utilizing them successfully.

Travel between Discontinuity Points is not instantaneous. Each transition lasts between 3 and 30 minutes. During that time the Helm, and other dynamic magick items, do not function, so the ship (and all personnel, of course) experience weightlessness. Static magick effects, such as the Nepheligenous Sphere, are not affected.

At this time only a fraction of the Discontinuity Points theorized to exist have been mapped. This includes the possibility (some reputable astromancers say probability) that all the portals of known Discontinuity and Polydiscontinuity Points have not yet been fully explored and mapped.

Spectral Class	Distance Between Discontinuity Points (AU)
Star Type	Minimum	Average	Maximum
Blue	504	1764	3,024
Blue-white	130	542.5	955
Argent	32	107	182
White	12	39.5	67
Lt yellow	4	14	24
Yellow	3	10.5	18
Gold	2	7	12
Orange	1	3.5	6
Dk orange	0.7	2.5	4.2
Red orange	0.2	0.7	1.2
Red	0.03	0.1	0.18