Incarnum World

The world has been thrashed, and darkness has overtaken.  The sun is gone, and only a few hours of moonlight gives any comfort.  Souls wander aimlessly, and the cost of wielding magic now drains the life essence from you, drawing you closer towards becoming a mindless lost soul.

The leylines have withered. The gods are gone. What remains is Incarnum — the divine residue
within mortal souls. It fuels magic. It resists darkness. It erodes under strain. When Incarnum
reaches 0, the soul fractures. A character reduced to 0 Incarnum becomes Possessed.

You have 100 Incarnum Maximum.  Refer to The Law of Incarnum.

The Law of Incarnum
Complete Player Guide to Soulbound Magic

Incarnum Strain (Cost of Casting)
Whenever you cast a 1st-level spell or higher, you must make a Constitution saving throw. DC = 10
+ the spell’s level. On a failure, you lose 3d6 Incarnum. On a success, you lose half (rounded
down). Lower-level spells are easier to control. Greater magic tears deeper into the soul.

Holy Spells Exception
Holy Spells do not trigger Incarnum loss. A Holy Spell is any spell that deals radiant damage,
contains the words holy, divine, or faithful in its name, or belongs to the School of the Moon.

Vile Foe
When first encountering Aberrations, Fiends, or Undead in a day, make a Wisdom saving throw
(DC 10 + half the creature’s Challenge Rating, rounded down, minimum 10). On a failure, lose
Incarnum equal to the creature’s Challenge Rating (minimum 1). Further encounters with the same
type that day require no additional saving throws.

Evil Creature Assault
Many creatures from The Fell deal spiritual damage in addition to physical harm. Such attacks may
directly cause Incarnum loss as specified by the creature or encounter.

Narrative Incarnum Loss
The DM may impose Incarnum loss to reflect trauma, dread, supernatural pressure, or mounting
tension.

Might of the Soul
As a bonus action, roll one of your Hit Dice. Gain that amount as temporary hit points and lose the
same amount of Incarnum. If multiclassed, choose which Hit Die to roll. This effect does not stack.
Temporary hit points last until your next long rest. You cannot reduce yourself to 0 Incarnum with
this feature.

Dark Whispers
When indulging in sin or temptation, you may roll 1d4, 1d6, 1d8, or 1d10. Lose Incarnum equal to
the result and add that amount as a bonus to one Ability Check, Saving Throw, or Attack Roll made
on your next turn. The DM determines when a meaningful temptation presents itself.

A Taste of Darkness
When reduced to 0 hit points, you may instead remain at 1 hit point. You lose half of your current
Incarnum (rounded down). This ability may be used once per long rest.

Regaining Incarnum - Short Rest
During a short rest, roll any number of unspent Hit Dice. For each die rolled, choose to regain hit
points, regain Incarnum, or split the total between both. Once rolled, the Hit Die is expended.

Regaining Incarnum - Long Rest
After a long rest, regain Incarnum equal to the highest of your Intelligence, Wisdom, or Charisma.

Pushing Past
You may take on Exhaustion to regain Incarnum equal to 1d10 × your new level of Exhaustion. 0 ®
1 Exhaustion: regain 1d10. 1 ® 2 Exhaustion: regain 2d10. 0 ® 2 immediately: regain 3d10 total. A
character dies at 5 levels of Exhaustion.