Altar

Dungeon features
Air	_ Altar
# Corridor	# Cloud
#. Drawbridge	+-| Door
. Doorway	{ Fountain
| Headstone	.  Floor
>< Ladder	. Ice
# Iron bars	} Lava
} Moat	# Sink
Solid rock	>< Staircase
\ Throne	^" Trap
# Tree	- | Wall
~ Vibrating square

Religion in NetHack
priests alignment alignment record altars atheism anger gods sacrifice prayer turn undead

An altar is a dungeon feature that appears in NetHack and is represented by an underscore, _. A temple is a special room that contains an altar and an aligned priest, or a high altar and a high priest.

An altar is co-aligned if its alignment matches your alignment and cross-aligned if its alignment differs from your alignment. An altar of Moloch is unaligned. To determine the alignment of an altar, either use far look or stand on it and use near look.

Most ways of interacting with an altar break atheist conduct.

Generation

Randomly generated altars appear in ordinary room and corridor levels in the Dungeons of Doom. There is an independent 1 in 60 chance of each non-special room containing an altar; this chance does not depend on dungeon level. A randomly generated altar has an equal probability of each of the three alignments and is never unaligned. A randomly generated altar will not be adjacent to a door (diagonal is okay), but otherwise can occupy any spot in the room not already occupied by something else.

A randomly generated altar may also appear as part of a randomly generated temple.

In addition, there are several guaranteed altars. Every layout of Minetown has a temple with a randomly aligned altar; except for Orcish Town, which has an unaligned altar (and no temple). Some quests have altars. In Gehennom, the Valley of the Dead has a temple of Moloch with an unaligned altar; Orcus-town has an unaligned altar; and Moloch's Sanctum has a temple of Moloch with a high altar.

Use

Detecting beatitude

If you drop an object on altar, the altar will reveal the beatitude of the object. (This works only if you drop the object, not if a monster drops the object or the object is thrown.) A black flash marks a cursed item, and an amber flash marks a blessed one. You cannot detect an item's beatitude if you are blind. You cannot detect whether an item is blessed or cursed if you are hallucinating, as the flashes will have hallucinatory colors; you can, however, detect uncursed items, as there will not be a flash at all.

Sacrificing corpses

Sacrificing fresh corpses is a useful way to reduce your prayer timeout, increase your luck, gain powerful artifact weapons, and improve your alignment (particularly if your god is unhappy with you). In SLASH'EM, you can also have wielded and worn items blessed and gain powerful minions through sacrifice. Sacrificing at the altar of another god has a chance of converting that altar to your alignment, potentially angering that god. Note that it also has a chance of converting you to that altar's alignment, angering your god and making it difficult or impossible to complete the quest if you haven't already done so.

Prayer

A prayer on a co-aligned altar has enhanced benefits.

Normal prayer timeouts apply when praying on altars.

Making holy/unholy water

If you drop one or more potions of water onto an altar and pray, the potions may become holy water or unholy water. A successful prayer on a co-aligned altar makes holy water. An unsuccessful prayer, or a prayer on a cross-aligned or unaligned alter, usually makes unholy water (but sometimes has no effect on the water). This occurs regardless of whether the water was blessed or cursed before. Be aware that prayer has other effects, especially prayer on a cross-aligned or unaligned altar.

Scaring monsters

Standing on any altar (even an unaligned altar) scares vampires as if you were standing on Elbereth or a scroll of scare monster. This does not break atheist conduct.

Misusing an altar

If you sit on, engrave on, or kick an altar, you will experience negative effects depending on the altar alignment and your alignment record. If the altar is co-aligned and your alignment record is greater than -rn2(4), you lose one point of wisdom and one point of alignment record; otherwise, if your luck is greather than -5; you lose 0-2 points of luck.

Misusing an altar does not break atheist conduct.

Digging an altar

If you (or a monster) zap a wand of digging downwards while on an altar, the digging ray is ineffective, and nothing further happens. If you break a wand of digging or apply a drum of earthquake, altars are not affected.

High altars

The three altars on the Astral Plane and the altar in Moloch's Sanctum are high altars. They act largely as normal altars, but cannot be converted under any circumstances; doing so will cause the god in question to zap you and, failing this, will summon three minions to protect the altar.

To ascend, you must offer the Amulet of Yendor on the co-aligned high altar.

The far look command does not reveal the alignment of a high altar, saying only aligne or unaligned. aligned does not mean co-aligned with you!

Strategy

An altar is an excellent source of artifact weapons, intrinsic protection, other intrinsic properties, spellbooks, holy water, nutrition, and other benefits. Because nutrition is available through prayer, it is possible to stay at an altar indefinitely, a practice known as altar farming.

Misusing an altar can be used deliberately lower your luck or alignment record to prevent crowning. You can use a ring of sustain ability or a noncursed unicorn horn to counter wisdom loss, and a MSGTYPE to hide the complaints from the altar's god.

To find the correct high altar on the Astral Plane, you can:

• visit each of the high altars
• zap a wand of probing at a high priest
• note if you are given sanctuary in a particular temple
• use a helm of opposite alignment to change your alignment opportunistically

History

In NetHack 3.4.3 and earlier, including variants based on those versions, pudding farming was a strategy for generating large numbers of corpses for altar fodder by repeatedly splitting puddings.

In NetHack 3.4.3 and earlier, including variants based on those versions, breaking a wand of digging or applying a drum of earthquake would destroy an altar.

In NetHack 3.4.3 and earlier, including variants based on those versions, the Astral call bug enabled players to find the correct high altar trivially.

Encyclopedia entry

Altars are of three types:
1. In Temples. These are for Sacrifices [...]. The stone
top will have grooves for blood, and the whole will be covered
with _dry brown stains of a troubling kind_ from former
Sacrifices.

[ The Tough Guide to Fantasyland, by Diana Wynne Jones ]

To every man upon this earth
Death cometh soon or late;
And how can man die better
Than facing fearful odds
For the ashes of his fathers
And the temples of his gods?

[ Lays of Ancient Rome, by Thomas B. Macaulay ]

Variants

Players of NetHack brass and SLASH'EM need to be wary when converting altars, because of the increased chance that the altar's original god will dispatch a minion against you. Players with a high luck will have fewer minions dispatched against them.

Even worse, there's an additional chance of one or more minions appearing post-conversion. In SLASH'EM, if you are at experience level 4 or above, there is a chance that "You feel (god) is very angry at you!" and the god dispatches two minions. Afterwards, you still have the original chance of another minion, as above. Again, luck is a factor.

In NetHack brass, you will always receive "You feel (god) is very angry at you!" For all experience levels, at least one minion will appear. Two rolls are made: the first from 0 to 9, the second from 0 to 19. For each roll, if your level is less than the generated random number, a post-conversion minion is summoned. Luck is not a factor. Thus in brass it is very dangerous to convert altars. You might convert an altar at experience level one and have to flee to another level from one minion, or three minions if the game rolled 0 twice, thus giving you no use of the converted altar. If converting an altar at experience level 7 or above, you might still get the pre-conversion minion, forcing you to fight as many as four summoned minions.

Also, there seems to be a possibility in SLASH'EM to have equipment being worn blessed if you sacrifice enough.

See also

• Prayer
• Sacrifice