Topic of the Month: Of Magic in Alphatia and the Hollow World

[Excerpted from the summarized version of a report with the same title by the Council of Alphatia to Empress Eriadna. Ed.]
Of Magic Working in the Hollow World.
Magic in the Hollow World is restricted because of a powerful spell cast by the Immortals, known as the Spell of Preservation, which seems to be maintained by the energy stream pouring out of the gate in the centre of the world (commonly named the Red Sun).
The following spells do not work in the Hollow World:
All spells of Divination and Communication (Schools of Lesser and Greater Divination; some spells from the School of Alteration).
All spells of Summoning and Conjuration (School of Conjuration/Summoning, some spells from the Schools of Invocation/Evocation and Shadow).
All spells of Instantaneous Transportation (Schools of Dimension and Shadow).
Of Magic Working on the Floating Continent of Alphatia.
Unlike the rest of the Hollow World, all kinds of magic work within the confines of the Floating Continent of Alphatia, to the limits of the skyshield surrounding it. Evidences show that such is the case only since the first of Nyxmir AY 2015 [Nuwmont 1, AC 1016. Ed.], where magic prior to the Day of Dread was restricted the same way as it was in the rest of the Hollow World. Since this corresponds exactly to the creation of a new sun by the Immortals (dubbed the Moving Sun, which orbits the Red Sun), it is speculated by various sages that it generates both the antidote to the mnemonic mineral disease and to the restricting effects on magic of the Red Sun. This hypothesis seems to be validated by the effects observed by spellcasters who did not expose themselves to the sun each day. The exact process of this counter-effect is unknown as yet, though, and how or why it interacts only with the skyshield around Alphatia and not the world below, or even other floating continents, remains a mystery under heavy investigation.
All wizards and priests that have absorbed mnemonic minerals potions in sufficient quantities have the ability to cast those spells that are allowed only on the floating continent. Spellcasters that didn't are restricted to the same spell range as any inhabitant of the Hollow World, though they can still use magical items embedded with the powers they can't personally wield. Any such magic items brought without Alphatia become inert until brought back, and spellcasters who leave Alphatia lose access to these extra spells which will fizzle if cast (or if their effect will cross the Alphatian skyshield, like teleporting to the surface world).
Addiction to mnemonic minerals bears some drawbacks, though, in addition to its scarcity. Firstly, spellcasters can no longer cast during the fortunately often short period between the illness (when the poisonous substance is flooding the body) and the adaptation by the metabolism, a very dangerous period of incapacitation that is the reason for some powerful magic-users' reluctance to trying it out. To remedy this situation, the council recommends that first level spellcasters are addicted during the course of their university studies, as the loss of power is less dangerous at that stage of their lives.
The second restriction is that mineral addicted spellcasters must remain exposed at least one day to the light of the Moving Sun (though this remains an hypothesis at this point; other have it that it is the light of the Red Sun instead, while other speculations suggest other seemingly fantasist reasons). Failing to do so reverses the adaptation of the metabolism to the presence of the mnemonic mineral, and restore the risk of falling ill again.
The detail of the process of becoming infected with (and benefiting of the effects of) mnemonic minerals is this one:
Ingest 30 doses of mnemonic mineral potions, maximum one per day. During that time you gain one additional spell of level 3.
Take additional doses until failing a save vs. poison and becoming ill. While drinking additional potions you still gain the additional spell.
Get exposure to the Moving Sun at least one hour a day until you fail another save vs. poison and becoming adapted. During that period you are without spells.
Keep on exposing to the Moving Sun one hour each day or risk becoming ill again as above. From now on you can cast any spell while on Alphatia. If you stop the sunbathes you still get to cast spells normally, but do not get an additional spell again.
Of Magic Unknown to Savage Hollow World Natives.
Not all spells are available in the Hollow World, but even less are known and used by the primitive natives of the place.
The following spells are useable in the Hollow World but are not known except in Alphatia:
Spells of Holding (School of Enchantment/Charm).
Spells of Charming and Commanding (Schools of Enchantment/Charm and Mentalism).
Spells of Immortality (School of Necromancy).
Various offensive spells (School of Force, various spells from the School of Invocation/Evocation and some spells of the School of Alteration).
Wish-like spells (note that those spells do not work if used to emulate spells that do not work in the Hollow World).
Various sophisticated spells (including but not limited to those from the Tome of Magic and the Spells & Magic or those from the most sophisticated Schools like Artifice or Geometry or any secret arts).
Magic-users simply do not have those spells in their spellbooks, while priests are not granted them by their Immortals, even if they should logically be in their Immortal's portfolio and even if the spells are granted to the Alphatian priests of the same deity.
The council strongly advises against revealing the secret of these spells, some of which powerful, to the natives of the Hollow World, unless it is in the higher interest of the empire.