School of Atomancy [Oddlands]

Disciples of the School of Atomancy, called Atomancers, practice a form of magic that blends arcane interactions with unstable primordial elements. The telltale signs of atomancy include detonations, chain reactions, and decay.

Atomancy is known for its ability to generate inordinate sums of energy from small amounts of rare earth elements which serve as spellcasting foci for practitioners of this magic.

The School of Atomancy originated in a powerful and influential city in the Oddlands that is thought to have been obliterated by its own hubris and the practice of Atomancy.

[Oddlands is a work-in-progress 5e setting developed by @mattdonatelli on Twitter. Send me playtesting feedback there!]

Atomic Shielding

Beginning when you select this school at 2nd level, you have proficiency with Weaver’s Tools. You know how to weave lead protection into your clothing that protects you while studying the rare earth elements used in Atomancy. This gives you advantage on saving throws against exhaustion caused by radioactive sources.

Unstable Spells

As a bonus action before casting, you may specify that you’re casting an unstable version of a spell. This utilizes your Atomancy spellcasting focus to convert half of the spell's damage to necrotic type.

Chain Reaction

When you roll a 20 on a ranged or melee spell attack, the spell is duplicated at its origin point. You may choose a new target within range for the cloned spell.

Arcane Half-life

Starting at 6th level, when the duration of one of your spells expires, you may roll a d20 and add your proficiency modifier. If your combined total is over 10, your spell continues for half the original duration of the spell. Each subsequent check at durations end raises the DC by 2. When you reach a point where the duration would be less than a complete round (6 seconds), or you fail a check, the spell effect ends.

Greater Chain Reaction

Upon reaching 10th level, your ability to cause chain reactions becomes stronger. Initial chain reactions now occur on a spell attack roll of 19 or 20.

Additionally, when a subsequent target is hit by one of your cloned spell attacks, you may make an additional chain reaction check. Roll a d20 for each target that is hit, and on a 20 the check succeeds.

If the chain check is successful, two additional clones of the original spell emanate from the hit target’s location. You may select up to two new targets within spell range of the struck target, but not including that target.

Meltdown

At 14th level, when your hit point total reaches 0, you may use your reaction to restore half of your maximum hit points and erupt with radioactivity. Every creature within 120ft of you must make a constitution saving throw with DC 12 plus your spellcasting ability modifier. Creatures within 60 feet of you make this check with disadvantage. Inorganic constructs are immune to this effect, as are you.

On a failed save, the creature must roll a d6. The result of that roll becomes their exhaustion level as they are poisoned by your radioactive fallout. On a successful save, the creature gains one level of exhaustion. You automatically succeed on this save.

You may use this ability once per long rest.