Phlogiston and Crystal Shells

Beyond the outermost planet of a sphere, it becomes possible to enter the Phlogiston, a mysterious ocean of rainbow and iridescent light. It is an extraplanar sea within which ships can journey to new spheres.
To enter the Phlogiston, travelers need to journey beyond the orbit of the outermost planet, and either find a natural “portal”, which can be time consuming, or create one of their own using specific spells or devices. (See new powers to do both). Portals are places in space where the Phlogiston and Wildspace meet, and ships can cross between the two. The rules are similar when approaching a system from within the Phlogiston.
The caster of a locale portal spell (or using a portal locator device) can find the nearest portal either into or out of the Phlo. The spell indicates direction and distance. In general, from any point in the outer edges of a system, the portals for a normal sized ship are from 2-20 days away from any location. At the GM's option, there may be more portals than normal available, less, or none at all. The spell may only be cast beyond the orbit of the farthest planet in a system.
Star systems are marked in the Phlogiston by massive shells of indestructible crystal. These crystal shells usually do not exist in the same plane as Wildspace, but there are some exceptions, in those systems where magic is particularly dominant.
The crystal spheres are definitely solid in the Phlogiston. They have no gravity (an exception to the rule that all large objects have gravity) . No magic has been found that can damage or alter the surface of a shell, except for those spells which cause portals to open. Even this, however, is believed to be nothing more than an artificial triggering of a natural phenomenon, since portals also occur naturally and seemingly at random.
There are some naturally occurring, persistent portals that appear as stars from the inner planets. These are rare, may be marked on star charts if they aren’t kept secret, and may be guarded if a system has a strong spelljamming civilization.
The Phlogiston is isolated from all other planes, and is beyond the influence of gods and other-dimensional creatures. Magic that summons or draws power from such beings or creatures, or otherwise requires access to other planes, does not function in the Phlogiston.
Phlogiston has varying thicknesses in space and forms dense rivers between planet-sized objects (such as the spheres themselves). Voyagers moving along these paths of concentrated phlogiston discover that the greater the density of the flow, the faster a ship can move . A ship can speed up and slow down by penetrating deeper into or raising itself out of these phlogiston rivers. Further, the speed of the ship is at least partially dependent on the surface area it presents to the flow, and so the sails carried by ships help to increase their speed in the interstellar ocean.

Navigation and Travel Times

Voyagers can move along the rivers of phlogiston at random or according to a planned course. Many of these rivers flow in both directions between two crystal shells. In some cases, a river flows in one direction only, forcing the voyager to follow a different course when returning home. Star charts will typically note which spheres are nearby and can be reached regularly, and which ones are not. Some spheres drift into and out of proximity with each other, so that just because you reach an area once does not mean that you will find it again.
The phlogiston stretches out in every direction, and rivers and streams in the phlo can likewise lead in any direction, though almost always to a sphere directly.
The sphere reached is random unless star charts are being used, with a successful Astrogation check (to find the right place to exit a sphere, enter the right flow, and if needed switch to a different river deep in the phlogiston).

• The roll can be supported by others with the Astrogation skill.
• A raise cuts the travel time (see below)
• A success indicates normal travel time (10d10 days) to the intended sphere.
• A failure indicates a random sphere is arrived at.
• A critical failure indicates the ship is wildly off course. Add an additional 10d10 days to the travel time, before arriving at a random sphere.

There are many major flow rivers that wind and cross through the Phlogiston, and each has a distinctive color scheme that makes it distinct from the others.
Because of the chaotic, shifting nature of the Phlogiston, travel times between spheres vary on every trip, even between the same spheres.

• On average, the travel time is 10-100 (10d10) days. (These dice do not explode)
• This can be reduced 25% with a Raise on an Astrogation role (indicating the navigator has been particularly effective to navigating the rivers of the Flow).
• This can also be reduced 25% with a Boating roll at -4 (either a crew boating roll, or a single Wild Card roll). This reflects the crew successfully "catching the wind" of deeper parts of the Flow.
• Both rolls can be supported to increase the chance of success (by someone with the appropriate skill).
• Draw for encounters typically 1x week (more on heavily traveled routes between the Triad, less on more obscure routes).

A ship can leave a river in the middle of the Phlogiston and attempt to travel across the “calm” parts of the Phlo. However, this is much more time consuming and difficult. It has been suggested that if you head in any direction within the Flow, you will eventually come to a crystal sphere, but this has not been proven. And there is no reason to believe the sphere would be close enough for your ship’s air envelope to last.
Sages believe that the relationship of position and distance between two systems in “real” space has no bearing on the spheres in the Phlogiston. Two spheres that are connected by a relatively brief trip through the Phlogiston might be thousands of light years away in “real” space, or in completely different galaxies.

Flammable Nature of the Phlogiston

Finally, the phlogiston is dangerously flammable. Any flame exposed to phlogiston causes the surrounding area (including the phlogiston-laden air envelope of the ship) to burst into flame. Because of this, all flaming light sources are extinguished by the crew before entering the Phlo.