Magic Changes

There are restrictions to magic in this campaign due to the Planar Boundary.

The Planar Boundary
In the world of Dungeons & Dragons, there is the Prime Material Plane. This is the physical world, where the PCs live.

Then there are the Inner Planes of Air, Earth, Fire, and Water, and other subplanes (like Shadow and Dust). Arcane magic, practiced by wizards, draw most of their power from these planes. These planes are interconnected by the Ethereal Plane.

Then there are the Outer Planes, places like Olympus and the Nine Hells. These are the realms of gods & devils; angels & demons. Divine magic, practiced by clerics, comes from these planes. These planes are interconnected by the Astral Plane.

In Kassithe, because magic is so young and undeveloped, there still exists a barrier -- known as the Planar Boundary -- that exists between the Prime Material Plane and these Inner and Outer Planes.

This has major effects on spells at the start of the campaign: These effects may change depending on the players' actions as they progress through the campaign.
 * Energy passes through the barrier normally. Spells like lightning bolt work just fine.
 * Physical items cannot pass through the barrier in either direction. Spells like teleport are blocked by the planar boundary (teleporting is basically using the Ethereal Plane). Same for bags of holding.
 * Creatures cannot pass through the planar boundary. PCs can't use an astral spell to travel the planes, and PCs can't summon elementals or demons.
 * Shadow creatures (like the unseen servant) can be summoned, they are more energy than physical and manage to pass through.
 * The planar boundary does not affect communication spells like commune or contact other plane.

Specific Spell Changes
These generalities have specific effects on D&D spells. Spell changes are given in alphabetical order:
 * Arcane Gate: not available
 * Astral Projection: not available
 * Banishment: not available
 * Blink: not available
 * Conjure Animals: this spell is different than in the book. The spell is more of a summons: the druid makes a call and nearby animals show up to assist in 2d6 rounds. Animals summoned depend entirely upon the terrain and the availability. The spell fizzles if there simply aren't any animals in range to be summoned.
 * Conjure Celestial: not available
 * Conjure Elemental: not available
 * Conjure Fey: like conjure animals above, this spell acts like a summons. The druid makes a call and nearby fey creatures show up to assist in 2d6 rounds. Creatures summoned depend entirely upon the terrain and the availability. The spell fizzles if there simply aren't any fey creatures in range.
 * Conjure Minor Elemental: not available
 * Conjure Woodland Beings: like conjure animals above, this spell acts like a summons. The druid makes a call and nearby woodland beings show up to assist in 2d6 rounds. Creatures summoned depend entirely upon the terrain and the availability. The spell fizzles if there simply aren't any woodland creatures in range. Also note this spell does work in other terrains, it could be "conjure desert beings" in the desert.
 * Demiplane: not available
 * Dimension Door: not available
 * Drawmij's Instant Summons: not available
 * Etherealness: not available
 * Forbiddance: not available, and actually not necessary
 * Gate: not available
 * Imprisonment: the "hedged prison" effect is not available, otherwise the spell works normally.
 * Leomund's Secret Chest: not available
 * Leomund's Tiny Hut: not available
 * Maze: not available
 * Planar Ally: not available
 * Planar Binding: not available
 * Plane Shift: not available
 * Teleport: not available
 * Teleportation Circle: not available

Magic Items
Magic items that duplicate or approximate these effects also do not exist. Magic items that create interdimensional space (like bags of holding) do not exist. Again, this may change as the players progress through the campaign.