|Cosmology / Powers and Deities / Dramatis Personae /
Rules and Mechanics / Character Creation / Equipment
The phlogiston (also known as “the Flow”) is a bright, extremely combustible gas-like medium that exists between the crystal spheres. A signature property of the substance is that it does not exist within the boundaries of a crystal sphere, to the degree that it cannot be brought into a crystal sphere by any known means up to and including the direct will of deities. Every crystal sphere floats in the phlogiston, very slowly bobbing up and down over time. Travel between crystal spheres is facilitated by the formation of “Flow rivers” — sections of the phlogiston which have a current and greatly reduce travel time. Travel through the “slow flow” (i.e. off the Flow rivers) is possible, but very dangerous.
Gravity is a constant earth-normal powered force. Every object exerts this, but the direction alters according to shape, and only objects of a certain size (generally about 25’ long) exert enough force for a gravity plane to develop. Spherical objects attract objects towards their surfaces uniformly, much as gravity works in our own universe. Objects with a more irregular shape develop a gravitational “plane” which extends along the most convenient axis, generally the longest. This plane works in both direction so that it is possible, for instance, to walk on the bottom of a ship.
Gravity planes exert a slight outward force, so that an object dropped overboard will oscillate across the plane until it settles there, and will then drift slowly outwards from the ship to be eventually expel from the air envelope.
This gravitational plane exerts a “field” which extends to the limit of a body’s air envelope. When two such fields come into conflict the gravitational field of the larger body dominates. This makes it dangerous to be out of pitch or alignment with a larger ship if you enter its gravitational field/air envelope. Specifically, this means that when a ‘jammer enters a planetary atmosphere the planet’s gravity becomes dominant. (You can walk on the bottom of your ship in space, but in a planet’s atmosphere you would fall off and land on your head.)
All bodies of any size carry with them an envelope of air whenever they leave the surface of a planet or other stellar object. Unlike real-world astrophysics, this air envelope is not dispersed by the vacuum of space. These bubbles of air provide breathable atmosphere for varying lengths of time, but 3 months is considered “standard”.
Traveling through the Flow
It is possible to physically navigate between the crystal spheres by sailing the phlogiston in mystic ships known as Spelljammers. Spelljamming is a dangerous and arduous endeveavor—making use of the portals within Nexus is far easier, though it does place the traveler at the mercies of the God-King and his concubines.