Can anyone help me because I can't find any reference to what, or how many Divine Spheres each Immortal allows to their clerics. I own the Karameikos, kingdom of adventure book, and it tells about them but don't specify which spheres they grant. Is there any book that has this information, or do I have to simply decide this as the DM? If so, how many primary and secondary spheres can an Immortal grant to their followers?
The 2nd Edition Red Steel / Savage Coast material provides suggestions for giving clerics different spell lists based on the sphere of their deities.
Matter. Major access to all, animal, elemental earth, plant, and summoning. Minor access to combat, creation, divination, and healing.
Energy. Major access to all, creation, elemental fire, sun, and weather. Minor access to combat, guardian, healing, and summoning.
Thought. Major access to all astral, divination, elemental air, and summoning. Minor access to charm, guardian, healing, and weather.
Time. Major access to all, creation, divination, elemental water, and healing. Minor access to animal, necromantic, plant, and sun.
Entropy. Major access to all, combat, divination, healing (reversed only), and necromantic. Minor access to elemental (reversed only), plant (reversed only), summoning, and weather.
Mystara is a world designed for BECMI D&D, which doesn't have the concept of Spheres. If you're playing AD&D 2nd edition in Mystara, you will have to decide on their Spheres for yourself.