Zerth mantras

In dNetHack, notdNetHack and notnotdNetHack, a zerth mantra is a type of passive ability that is granted from two artifacts: The Sky Reflected and The Amalgamated Skies.

Description

For a particular mantra to be learned, the sum of the hero's intelligence and wisdom must exceed the listed value in the table below, after which the mantra is constantly applied:

Name	Stat requirement	Effect
Missiles of wrath	Sum > 21, Wisdom < 8, Sanity < 25	Magic missile spell damage dice gain +2 faces, dealing +1 damage per die on average.
Scripture of steel	Sum > 23	Pets get +1 AC, +1 to-hit, and +1 level on their monster magic resistance rolls. When wielding the Sky Reflected, the Silver Sky or the Amalgamated Skies, the hero gains an additional to-hit bonus equal to (1 + weapon enchantment).
Submerge the Will	Sum > 27	While the hero has spell protection, they take half damage from magical attacks. This stacks in a multiplicative manner with half spell damage and vaul. Pets gain +10 monster magic resistance.
Vilquar's eye	Sum > 29	While the hero is invisible, monsters must roll magic resistance in order to sense their location. Ordinarily, monsters may sense an invisible hero via non-visual means or via the see invisible property.
Power of one	Sum > 31	The hero's strength is set to 25 when wielding the Sky Reflected, the Silver Sky, or the Amalgamated Skies.
Balance in all things	Sum > 34	While the hero has spell protection, if you are damaged by an attack all adjacent monsters take 8 damage.
Work of patience	Sum > 37	Pets get +8 to their XP threshold, allowing them to more easily reach higher levels. While the hero is 30th level, the force bolt spell deals an additional 10d12 damage.
Zerthimon's focus	Sum > 40	Gith silver swords, including the Silver Sky and the Amalgamated Skies, have an increased chance of dealing bonus damage based on the hero's sanity. The bonus is +15% above 95 Sanity, +10% above 90, +5% above 85, and +0% otherwise, and stacks in an additive manner with the insight-based bonus damage rates.

Strategy

Obtaining the missiles of wrath requires at most 7 Wisdom and at least 15 Intelligence, making it a challenging combination of stats to attain.

Origin

The mantras are loosely based on the spells learned from the Unbroken Circle of Zerthimon in Planescape: Torment, and the reign of anger spell from the same game. The ability scores required to learn each mantra are based on the stats required to learn the corresponding spell from the Unbroken Circle. The challenging-to-obtain combination of stats required for the missiles of wrath mantra are a reference to the fact that the corresponding reign of anger spell is unlearnable in Planescape: Torment, and so can only be cast by the character that begins knowing the spell, despite having an icon that suggests that it can be learned from the Unbroken Circle.