Over the last two weeks I ran a short Dungeons & Dragons adventure using the Planescape setting. Planescape adventures normally involve travelling between different planes of reality, which often changes the effects of magic. The laws of a particular plane tend to alter whole schools of magic, so this has been a good excuse to brush up on the eight schools. (I’ll often be asked by a player what kind of magic is being used in a situation, and won’t be able to tell them.)
Schools of Magic
Abjuration magic is protective.
Conjuration magic summons things from other places.
Divination magic provides information.
Enchantment magic influences minds.
Evocation magic produces different kinds of energy.
Illusion magic deceives the senses of others.
Necromancy magic interferes with life and death.
Transmutation magic alters the nature of things.
Magical effects on Avernus
As I said earlier, the laws of various planes change the way magic works. There is a whole lot of material from Second Edition D&D that provides information about this, but it doesn’t all translate neatly into Fifth Edition D&D. Our short adventure today was set on Avernus, the first layer of Baator (similar to Dante Alighieri’s conception of Hell), so I had a look at the magical conditions described in Second Edition’s Planes of Law. This is how I adapted the conditions for our Fifth Edition adventure:
Abjuration and Transmutation
Because abjuration and transmutation magic alter the natural properties of things, both of these schools of magic are considered to be in conflict with the lawful alignment of the plane. I decided I would require a successful DC 15 Arcana or Religion check to cast an abjuration spell. (Arcana for an arcane spellcaster. Religion for a divine spellcaster.)
In Baator, conjuration spells require a ritual in order to bind any creature that has been summoned. I decided I would require a DC 15 Arcana or Religion check to determine the success of a binding ritual. If the binding was not successful, the summoned creature would be in control of it’s own actions, and would likely be pretty angry about being summoned to Baator…
Divination spells cast on Baator always show negative outcomes, with at least a grain of truth. Divination magic is also likely to attract the attention of baatezu (devils).
Enchantment and Illusion
Enchantment and illusion spells are not altered.
Evocation spells may be altered depending on the layer and the kind of energy they produce. On the layer of Avernus, fire and earth energy are both more effective. I decided I would probably allow players to cast fire and earth spells as though they were at a higher level, but wasn’t totally sure if this would be appropriate.
Necromancy spells that grant healing require a successful DC 15 Arcana or Religion check. Necromancy spells that cause damage or pain; or that control undead, can function as though they are one level higher.
Wild magic isn’t a school of magic, but it is effected by the lawful nature of Baator. I decided that the lawful nature of Baator would stop wild magic sorcerers from experiencing wild magic surges or from using any of their wild magic features.