Mjollnir

)   Mjollnir
Base item	war hammer
Damage vs. small	1d4+1 +1d24
Damage vs. large	1d4 +1d24
To-hit bonus	+1d5
Bonus versus	not shock resistant
Weapon skill	hammer
Size	one-handed
Affiliation	neutral (Valkyrie)
When carried	(none)
When wielded	throwable
When invoked	(none)
Base price	4000 zm
Weight	50
Material	iron

Mjollnir (colloquially Mojo) is a neutral artifact weapon. Its base item is a war hammer. It is a reference to Mjölnir, Thor's hammer from Norse mythology.

Generation

Mjollnir is eligible for random generation; a war hammer has a ¹⁄₄₀ chance of being Mjollnir, or ¹⁄₂₀ if Ogresmasher has already been generated. Any neutral character may receive Mjollnir as a random sacrifice gift. It's also the guaranteed first sacrifice gift for Valkyries; like all guaranteed gifts, its alignment will be adjusted to match your starting alignment.

Effects

Against monsters without shock resistance, Mjollnir has +d5 to hit and deals d24 extra damage. It may destroy wands and rings in the target's inventory, regardless of whether they have shock resistance.

If you have 25 strength (usually achieved by wearing gauntlets of power) and are wielding the non-cursed Mjollnir, you can throw it. If you are a Valkyrie, Mjollnir will return to you 99% of the time. If it returns, and you are not confused, stunned, blind, hallucinating, or fumbling, you will catch it 99% of the time. If you fail to catch a returning Mjollnir, it has an equal chance of falling to your feet or striking you, dealing damage as well as possibly destroying wands and rings.

Mjollnir's lightning also wakes nearby monsters.

Strategy

Very few monsters in the game resist lightning damage, and Mjollnir does a lot of it, making it an excellent weapon. For much of the game only three dangerous monsters are resistant to lightning: blue dragons, which are rare, electric eels, whose attacks are easily countered, and energy vortices. Mjollnir does very little damage when fighting energy vortices and also does not provide shock resistance against their attacks, so they are the primary danger when using this weapon. As one reaches the Castle, arch-liches may also become a problem.

In the endgame weapon-wielding angelic beings, hostile aligned and high priests and all the Riders will also be a major problem for Mjollnir. One of the draining artifacts (The Staff of Aesculapius and Stormbringer) is a good complement weapon since only two monsters, arch-liches and Death, are both shock and drain resistant.

Mjolnir has a small chance of destroying wands and rings in a monster's inventory. In practice, this is rare because even intelligent enemies don't pick up or carry rings and Mjolnir will usually kill the monster before its wands are destroyed.

Beware throwing Mjollnir at a disenchanter: Mjollnir still has a ten percent chance of being disenchanted. If a thrown Mjollnir is disenchanted, you will not receive a warning as you do for hitting a disenchanter in melee combat ("Your Mjollnir seems less effective").

Monster resistances

Notable monsters that do not have shock resistance:

• All monsters in the ​& major demon class, except the Riders
• The Wizard of Yendor
• Elementals

Notable monsters that do have shock resistance:

• The Riders
• Arch-liches
• Archons, Angels, and Aleaxes
• High priests and aligned priests
• Lightning-themed enemies (e.g. storm giants and blue dragons)
• Puddings, green slimes, and gelatinous cubes

Average damage calculation

The average damage calculations in the following table do not include bonuses from weapon skills, strength, or from using a blessed weapon against undead or demons.

Weapon	Shock resistant		Not shock resistant
	Small monster	Large monster	Small monster	Large monster
+0 Mjollnir	$\frac{1+4}{2}+1=\bold{3.5}$	$\frac{1+4}{2}=\bold{2.5}$	$\frac{1+4}{2}+1+\frac{1+24}{2}=\bold{16}$	$\frac{1+4}{2}+\frac{1+24}{2}=\bold{15}$
+7 Mjollnir	$\frac{1+4}{2}+1+7=\bold{10.5}$	$\frac{1+4}{2}+7=\bold{9.5}$	$\frac{1+4}{2}+1+\frac{1+24}{2}+7=\bold{23}$	$\frac{1+4}{2}+\frac{1+24}{2}+7=\bold{22}$

History

Mjollnir in its present form first appeared in NetHack 3.0.3. It replaced a lucern hammer named Thunderfist, which also dealt lightning damage and appeared as early as NetHack 3.0.0. The original programmer of Thunderfist perhaps did not realize that a lucern hammer is a polearm.

The present throwing behavior (25 strength needed, returns to the hand of a Valkyrie) first appeared in NetHack 3.1.0.

SLASH'EM

Mjollnir's weak base damage is somewhat ameliorated in SLASH'EM, where it is instead a heavy hammer with base damage of 1d6 against both small and large foes, as well as doing a flat +24 damage instead of a die roll up to that amount. Otherwise it remains unchanged, although the different behaviour of gauntlets of power means that obtaining the strength to throw Mjollnir is more difficult than in NetHack.

Average damage calculation

We assume the player has expert skill in hammer, which gives a +2 damage bonus. A blessed weapon deals 1d4 extra damage against demons and undead. The worst case scenario is against a shock resistant, non-undead, non-demon monster. The best case scenario is against a non-shock resistant, undead/demon monster.

Weapon	Against regular non-shock resistant monsters	Worst case scenario	Best case scenario
Uncursed Mjollnir + 0	$\frac{1+6}{2}+24+2=\bold{29.5}$	$\frac{1+6}{2}+2=\bold{5.5}$	$\frac{1+6}{2}+24+2=\bold{29.5}$
Blessed Mjollnir +7	$\frac{1+6}{2}+7+24+2=\bold{36.5}$	$\frac{1+6}{2}+7+2=\bold{12.5}$	$\frac{1+6}{2}+7+24+2+\frac{1+4}{2}=\bold{39}$

The largest damage boost in vanilla NetHack, percentage-wise, is a +0 Mjollnir attacking regular non-shock resistant large monsters. (+68.6%)

Encyclopedia entry

Forged by the dwarves Eitri and Brokk, in response to Loki's
challenge, Mjollnir is an indestructible war hammer. It has
two magical properties: when thrown it always returned to
Thor's hand; and it could be made to shrink in size until it
could fit inside Thor's shirt. Its only flaw is that it has
a short handle. The other gods judged Mjollnir the winner of
the contest because, of all the treasures created, it alone had
the power to protect them from the giants. As the legends
surrounding Mjollnir grew, it began to take on the quality of
"vigja", or consecration. Thor used it to consecrate births,
weddings, and even to raise his goats from the dead. In the
Norse mythologies Mjollnir is considered to represent Thor's
governance over the entire cycle of life - fertility, birth,
destruction, and resurrection.