Auras are effects surrounding units that rapidly exert their effect in "pulses" on nearby squares of the battlefield. Each aura has a value which primarily governs the rate of activation but also the area the aura covers. For unit abilities, this is typically denoted in the ability description. Whether an aura produces any or multiple effects is checked every 320 ticks (or 23.4375 times a round), much like most Battle Enchantments ¹⁾. Some auras produce no visual effect on the squares they affect.

The mechanics by which an aura strikes squares are shared amongst all the different aura types and are discussed below.

There are a wide variety of auras with different effects:

Aura	Effect	Notes
Chill	Creates a cloud that inflicts 2 AN cold fatigue damage per pulse (the base cloud damage is 5, but divided by 3 and rounded up due to being a cloud).	Aura value is increased by 1 per Cold scale but decreased by 1 per Heat scale. If there is a snow storm in the province, the aura value is increased by 2. If the final aura value is 6 or less, the resulting clouds have lingering 1, otherwise they have lingering 2.
Disbelieve	Inflicts 999 AN magic damage on illusions, with a magic resistance check to negate the effect.	This aura is considered an Astral effect for the purposes of magic resistance.
Fear	Fear effect. Magnitude is (aura strength/5), rounded down, plus 3. Affects enemies only.	Has no effect if the aura value is less than 5, though this has no impact on an unmodded game. The aura value is increased by 6 for the purposes of generating pulses.
Heat	Creates a cloud that inflicts 2 AN heat fatigue damage per pulse (the base cloud damage is 4, but divided by 3 and rounded up due to being a cloud).	Aura value is increased by 1 per Heat scale but decreased by 1 per Cold scale. Rain (but not snow) further reduces the aura value by 2. If the final aura value is 6 or less, the resulting clouds have lingering 1, otherwise they have lingering 2.
Mind Slimer	Affected units become slowed.	Mindless units are unaffected.
Plague (from Plague and Woundflame)	Affected units must make a magic resistance check or catch the plague, taking 1d2 health damage and 1d4 fatigue damage every turn, as well as gaining this aura themselves. Inanimate units are unaffected.	This aura always has a value of 2. This effect is considered to be a Death effect for the purposes of magic resistance.
Plague Carrier	Affected units must make a magic resistance check or become diseased. Inanimates are unaffected.	This effect is considered to be a Death effect for the purposes of magic resistance.
Poison Cloud	Generates clouds with lingering 2 that inflict 1 AN poison damage per pulse (the base cloud damage is 2, but divided by 3 and rounded up due to being a cloud).
Sleep Aura	Affected units must make a magic resistance check or fall asleep. No effect on friendly, Mindless, Inanimate, or Undead units.	This effect is considered to be a Nature effect for the purposes of magic resistance.
Soul Vortex	Affected units must make a magic resistance check or suffer 1 AN life draining. Inanimate units are unaffected.	This aura always has a value of 8. This effect is considered to be a Death effect for the purposes of magic resistance.
Unused Aura (Unit Effect with ID 326)	Affected sacred units take 15 AP fatigue damage.	There is no known source of this effect outside of modding. It produces the same particles as Sleep Aura does.

Each pulse hits only a single square.

1. The probability of generating one or more aura pulses each check is (aura value)/24. Probabilities greater than one are guaranteed to produce at least one pulse.
2. Subtract 24 from the aura value. There is then a (new aura value)/24 to generate an additional pulse. This step continues until a new pulse is not generated.
3. Pulses are then placed, at random, in squares near the unit. If the pulse being placed is one of the first three for this check, or the final aura strength after subtractions is less than 10, the pulse appears in one of the nine squares in a 3x3 square around the unit. Otherwise, the pulse appears in one of the 25 squares in a 5x5 square around the unit. Successive pulses spawn centered around the square the last pulse was generated, which may cause auras to reach further from the unit that spawned them once aura values reach 25 or higher.

Auras with a value over 600 follow different mechanics, hitting squares anywhere on the battlefield at random. In an unmodded game this only concerns the Doom Horror Kurgi - Slave to Unreason which has a Mind Slime value of 665:

If the aura value is 666 or higher, 2.0625% of the battlefield is struck every 320 ticks. If the aura value is between 601 and 665 inclusive, 1.03125% of the battlefield is struck instead.