The crystal spheres are definitely solid. They have no gravity along either their interior or exterior sides (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 natually and seemingly at random. They are apparently immune to the effects of wishes and even the wills of the outer planar powers (though this does not rule out the possibility that the outer planar powers created them- perhaps they were wise enough to prevent even their own tampering).
The crystal shell is an impassable barrier to space voyagers unless they are properly prepared or very fortunate. Five methods are known for getting from one side of a crystal sphere to another 1) It can be bypassed entirely with a teleport or dimension door spell. The traveller blinks from one side of the shell to the other without physically crossing the shell. Only a magical item or magical spell can effect such a transfer. 2) A phase door spell or magical device which duplicates that spell allows a ship or portion of the shell to become immaterial so the ship can pass through. 3) Naturally occurring portals pierce the shell in various locations at random and unpredictable intervals. Looking for such a portal can be a time-consuming task.
4) In some systems, stars are located around the fringes. Occasionally, such stars are themselves portals to other locations which can be accessed by diving into the heart of the star. Such portals are very rare; voyagers definitely should check local listings before incinerating themselves in an unknown situation. 5) The legendary Spelljammer and creatures such as space dragons seem to have an innate ability to open portals to the phlogiston. These portals close slowly over a long, so other ships can sometimes pass through them. From outside a sphere, these portals are easily visible. Note that portals as discussed here are merely simple doors allowing passage from one side of a crystal shell to the other. They are not gates and they do not allow transit between dimensions. Magic that relies on other planes or other dimensions is notoriously unreliable when case in close proximity to a crystal shell.
The crystal sphere itself represents the outer limit of the influence of gods and other-dimensional creatures. Magic that summons or draws power from beings or creatures does not function outside these bounds. Much of the decision as to what will and will not work is left to the individual DM, but this restriction definitely does not apply to priest spells of levels 1 and 2. Those fantasy systems with stars in the night sky often have these stars mounted along the inside of the crystal sphere, however. Within some spheres the stars are small portholes looking out on the phlogiston, in some they are painted lights along the interior, in some they are great cities inhabited by alien creatures, and in others they are great bowls of fire held aloft by huge statues of forgotten gods.
Oh you get me ready In your '56 Chevy Why don't we go sit down in the shade Take shelter on my front porch The dandelion sun scorching Like a glass of cold lemonade I will do the laundry If you pay all the bills Where is my John Wayne Where is my prairie song Where is my happy ending Where have all the cowboys gone
Outside and between the crystal spheres is a turbulent, rainbow ocean of flammable ether called the phlogiston. The phlogiston is applied equally to both the multicolored medium and to the entire region surrounding the crystal spheres. 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. Stellar distances can be covered quickly in such areas. Further, the speed of the ship is at least partially dependent on the surface area it presents to the flow, so many ships carry sails to increase their speed in the interstellar ocean.
Join the spam. Gravity works in phlogiston the same way it does in wildspace. Down is directed tower the major axis of the ship. Phlogiston is none of the four elemental matters. It is neither air nor earth, fire nor water. It cannot be produced of brought inside the bounds of a crystal sphere. If an attempt is made, whether by physical or magical containment, the phlogiston inexplicably dissipates, leaving no trace. Phlogiston simply cannot exist within wildspace or on the surface of a planet.
Why don't you stay the evening Kick back and watch the T.V. And I'll fix a little something to eat Ohh I know your back hurts From working on the tractor How do you take your coffee my sweet I will raise the children If you pay all the bills Where is my John Wayne Where is my prairie song Where is my happy ending Where have all the cowboys gone I will post the video eventually.
