In recent versions of
Nethack (3.3.0 and later) and
Slash'Em,
there are several voluntary
challenges which the computer keeps
track of for you. The challenges range from never wishing for an
artifact, through
illiteracy, to
pacifism (not killing
anything). They are
voluntary in the sense that the game does not
tell you "You cannot read the scroll because you are illiterate" - it
lets you read it and notes that you are no longer illiterate. To see
which challenges you have adhered to so far, use the #conduct command.
There are three challenges involving dietary restrictions:
vegetarian, vegan, and foodless. Note that the restrictions
only affect the character's diet; a vegan is perfectly free to wear
gray dragon scale mail. These challenges derive their difficulty
from the problems they cause with gaining nutrition and
intrinsics. The nutrition problem can be ameliorated by wearing a
ring of slow digestion, and if your character is not fasting,
soldiers' barracks are a good source of vegan food. The intrinsics
problem is a bit trickier. Vegetarian and vegan characters can gain
all the usual resistances other than disintegration resistance by
eating gelatinous cubes, but must obtain telepathy by prayer (or in
Slash'Em, from a blessed potion of ESP). Foodless characters may have
to do without some intrinsics. In Slash'Em, you are granted fire,
cold, sleep, shock and poison resistance when you are crowned - but
if you're going foodless, you may not want to be crowned, because
prayer could be a major source of nutrition for you. Monks are
probably the best class for the foodless challenge, since in Nethack
they gain all the usual resistances as they gain levels.
Atheism, in Nethack and Slash'Em, means that you attempt to survive
without any help from the gods as a matter of principle - so no
praying, sacrificing, buying protection, or dropping things on altars
to see whether they are blessed or cursed. Offering the Amulet of
Yendor to your god does not violate this challenge. The main
difficulties involved in ascending as an atheist are the lack of holy
water and artifact weapons.
Illiteracy means what it sounds like, but the precise rules are
different in Nethack and Slash'Em. Illiterate characters are
never permitted to read a scroll, spellbook, fortune cookie, or
T-shirt, write a scroll or spellbook, or engrave anything other than a
single "x". In Slash'Em, they are not allowed to read engravings of
anything other than an "x" either. Reading the Book of the Dead
does not count, the explanation being that it reads you rather than
you reading it. The illiterate challenge is somewhat easier in
Slash'Em than in vanilla, because you can pay shopkeepers to
identify your stuff and enchant your weapons and armour.
Weaponless conduct (never hitting with a wielded weapon) is a fairly
hard challenge. It is also easy to break by accident (mistakenly
bashing a monster with a pick-axe), but there is a patch which makes
the game ask for confirmation before doing this. I have achieved
"weaponless" ascensions with a wizard who mostly used magic but also
a bunch of highly enchanted throwing daggers and a monk who used
martial arts.
Pacifism is a particularly hard challenge which I do not know much
about. It means that you do not cause the death of any monster,
although it is OK to injure them. Amazingly, pacifist ascensions
have been done. One helpful pacifist strategy is to have a horde of
powerful pets to do your killing for you.
Genocideless conduct is fairly hard, because it means that you'll
have to be able to cope with liches and mind flayers (normally on
everyone's must-genocide list). The best way to survive is to pack a
large supply of cockatrice eggs and throw them at any master lich,
arch-lich or (master) mind flayer who comes near you.
Polypileless conduct means that you never polymorph an
object (polypiling means polymorphing a pile of objects). I find this
challenge fairly easy, because when I was learning to play Nethack,
first I didn't know about polypiling, and then I preferred to use
wands of polymorph on my pets. It is possible to break this conduct
accidentally, e.g. if you test random potions by dipping objects.
Polyselfless is a challenge which I ignore. It's probably intended
to forbid spending your time as a powerful monster or laying
cockatrice eggs for stoning or dragon eggs for pets, but in a typical
game I am likely to violate it by stepping on a polymorph trap. I
didn't want to polymorph, and nothing good came as a result, but it
was still in violation of the challenge.
Wishless is a tricky challenge because it makes it harder to acquire
your ascension kit, particularly dragon scale mail, which has to
wait until you meet adult dragons. Unfortunately, it is possible to
violate the wishless challenge by accident. For example, you can get
wishes from thrones. According to Pat Rankin, the next version of
Nethack will allow you to reject a wish by wishing for "nothing". A
related minor challenge is not to wish for artifacts.
Celibacy is a challenge which only officially exists in Slash'Em.
It makes it more difficult to gain levels, and characters with low
charisma are prone to being forcibly seduced. This is a
particular problem for monks in vanilla Nethack, as they cannot wear
body armour.