# Lycanthropy
Lycanthropy is an intrinsic property that appears in NetHack.
Lycanthropy is conveyed through being bitten by a werecreature – a werejackal, wererat, or werewolf – as well as eating their corpses. Wielding Werebane prevents lycanthropy from being transferred via bites. Being given lycanthropy from an attack abuses your constitution, and eating a werecreature corpse is considered cannibalism if you are human.

Contents

1 Description

1.1 Silver-hating
1.2 Animal abilities

2 Strategy

2.1 Prevention
2.2 Curing and mitigation
2.3 Lycanthropy and pets

3 History
4 Origin
5 Messages
6 Variants

6.1 SLASH'EM

7 References

Description
Lycanthropy confers intrinsic drain resistance and hungerless regeneration, and also transforms you into your animal form at regular intervals: during daytime hours, you have a 1⁄80 chance each turn to change forms, and during the night you have a 1⁄60 chance each turn.[1] Depending on the animal form, you will shrink out of your armor and even break some of it, and your animal forms also have much lower carrying capacity; being killed while in animal form will return you to your normal form until the next transformation.
Werecreatures are the only monsters to have intrinsic lycanthropy - other monsters will not get lycanthropy from being bitten by a werecreature or eating one's corpse of a werecreature (though the corpse being poisonous can deter a pet from eating it).
Quaffing a potion of holy water will cure the lycanthropy and return you to your normal form if possible;[2][3] quaffing unholy water will immediately cause you to shift to your animal form. Inhaling the vapors of either potion will shift you to your normal form or animal form, respectively. Polymorphing with lycanthropy will toggle between both forms.

Silver-hating
Lycanthropes are also silver-hating creatures: if a player is given lycanthropy, they become vulnerable to damage from silver weapons and other objects. Additionally, they cannot handle any silver-based items in either form - any silver items being worn or wielded when the player is afflicted with lycanthropy will be forcibly dropped, with 1d10 points of damage dealt for each silver item. This check will also cause the player to "retouch" everything in their inventory, meaning that they may also take artifact blast damage as well if they are carrying any cross-aligned or cross-role artifacts.

Animal abilities
As an animal, the player has much lower carrying capacity than normal and cannot wear any armor; werejackals and wererats will be forced out of their armor and drop it, while werewolves will destroy their shirt, cloak, and body armor and drop any remaining armor. Even after shedding your armor, your encumbrance level  will often be at strained or worse, and it is not uncommon to end up overloaded as a result.
While in animal form, using the #monster command will call for help by summoning a few tame monsters of the same species as the player to your side (e.g., using #monster as a werejackal will call jackals, coyotes and foxes). Calling for help this way requires 10 power and exercises Wisdom when used successfully.

Strategy
Between the many setbacks of animal forms, the loss of armor with each transformation and the debilitating weakness to silver, lycanthropy is generally considered undesirable. The property does also have two notable benefits, however: drain resistance and regeneration, which are conferred alongside lycanthropy, and the ability to summon tame monsters.

Prevention
Naturally, one of the easiest ways to deal with lycanthropy is to avoid catching it in the first place: A ring of protection from shape changers will lock werecreatures in their humanoid form, ensuring they cannot bite you. Wielding Werebane will also prevent their bites from infecting you and can make short work of hostile werecreatures itself.
In lieu of reliable protection, high magic cancellation (e.g. from a cloak of protection) can significantly reduce the chances of infection. Another good prevention method is to kill werecreatures before they can reach melee range - more often than not, many characters will find a suitable projectile weapon or attack wand before they encounter one. Silver weapons are typically quite rare, but can deal enough damage to dispatch a werecreature quickly even if you lack skill in that weapon. Pets are also a valuable resource in keeping a werecreature off your back, especially if you can get them between you and the hostile monster.

Curing and mitigation
Even if you cannot reliably prevent a lycanthropy infection, there are various means to manage or even cure the condition. An amulet of unchanging or ring of polymorph control can prevent unwanted transformations as long as you are conscious and not stunned, asleep, or confused[4] - the tradeoff for this is an inability to pick up or use any silver objects until you can cure the lycanthropy, as well as taking up a ring or amulet slot for that duration.
The following methods can cure lycanthropy:

Eating a sprig of wolfsbane.[5]
Quaffing a potion of holy water.
Praying to your god successfully, as lycanthropy is considered a major trouble.[6]
If all else fails, you can force yourself to transform back from animal form by dropping your HP to zero, e.g. kicking a wall repeatedly, then gradually make your way forward until you can wait out any prayer timeout or else find a means of stopping or curing the transformations. Letting monsters kill you in animal forms is possible but tricky, due to lycanthropy giving intrinsic regeneration. Unfortunately, you will also have to consider leaving behind much if not all of your current inventory, in order to avoid being immobilized by its weight if another shift occurs.

Lycanthropy and pets
The monsters summoned using the #monster command are generated tame and act as normal pets. This can be used to acquire a very large number of jackals, rats, or wolves, which you can use as temporary meat shields at bare minimum - pets that survive can then be polymorphed (usually via wand or polymorph trap) into much better pets. Very low-level characters will have trouble using this command early on, as the animal form will have much lower maximum power, and repeated "deaths" in animal form will usually result in even lower maximum power the next time you shift into animal form.

History
Lycanthropy first appears alongside werecreatures in NetHack 3.0.0.
The full-inventory "retouch" from being given lycanthropy was introduced in NetHack 3.6.0.

Origin
The word "lycanthrope" (from ancient Greek λύκος [lýkos, "wolf"], άνθρωπος [ánthropos, "man"]) simply means "werewolf". In Dungeons &amp; Dragons, which NetHack heavily borrows from, the term is extended to apply to all shape-shifting were-creatures.

Messages
You feel feverish.
You were given lycanthropy from a werecreature's bite.
You can't handle your foo!
The player was wielding a silver weapon or wearing a silver item at the time they were given lycanthropy, and is forced to drop it.
You lack the energy to send forth a call for help!
You tried to use the #monster command while shifted to your animal form, but do not have enough power.
You feel purified.
You successfully cured yourself of lycanthropy.
Variants
SLASH'EM
SLASH'EM adds several new werecreatures (and thus more potential sources of lycanthropy). A blessed potion of amnesia can cure lycanthropy.
The lycanthrope is a new starting race in SLASH'EM that always begins with the lycanthropy intrinsic; they will always be werewolves, although they will automatically remove their armor before transforming rather than destroy it (unless it is cursed).
In addition, the doppelganger race gains intrinsic polymorph control by reaching level 9, allowing them to mitigate the side effects of lycanthropy in a manner similar to wearing the ring.

References

↑ allmain.c in NetHack 3.4.3, line 267

↑ potion.c in NetHack 3.4.3, line 467: Code path for chaotics

↑ potion.c in NetHack 3.4.3, line 483: Code path for nonchaotics

↑ you_were in were.c

↑ eat.c in NetHack 3.4.3, line 1681

↑ pray.c in NetHack 3.4.3, line 169