There are various gods worshipped by the population of the Frost-Bitten lands, from the Lawful monotheistic god Svarog, through the triune Zorya to the numerous Lords of Chaos (AKA Demon Lords). Alignment is more important in matters of religion than in any other aspect; Lawful characters worship Svarog; Neutral characters can worship any god; and Chaotic characters worship the Lords of Chaos. Clerics must be of the same alignment as their god(s).
is the Lawful god, a smith-god who, according to legend, forged the
world out of molten iron and rock. Is was originally a Dwarven
monotheistic god, but Dwarven missionaries have brought this faith (as
well as literacy and the knowledge of steel-working) to Humanity after
Mankind was liberated by the Dwarves from the bondage of the Dark Elves.
Clerics of Svarog admire craftmanship and technology, grudgingly accept
the older Zorya worship and Lawful or Neutral Arcane magic, but must
make an effort to root out the Lords of Chaos wherever their
cult-worship emerges. All Dwarven Craftpriests worship Svarog and are,
are three Neutral goddesses: Zorya Utrennyaya (Morning Star; the
Maiden), Zorya Vechernyaya (Evening Star; the Mother) - and Zorya
Polunochnaya (Midnight Star; the Crone). They are always worshipped
together as three parts of the Cycle of Life. This faith is very
tolerant - even outright supportive - of most Arcane magic, except for
necromancy, grudgingly accepts the Svarog worship, dislikes the Lords of
Chaos (but is far less zealous about destroying their worship compared
to the Svarog clerics) and dislike technology when it interferes with
the natural order. Most priests of the Zoriya are female, usually
Bladedancers (ACKS Core) or Priestesses (ACKS Player's Companion) while
priests of the Cleric class are rarer.
The Lords of Chaos are legion, all Chaotic to the core:
Berstuk - the mad god of Forests and Wild Beasts (think of a 'male' Shub-Niggurath).
Chernobog - the Black God; the Patriarch of Chaos (think of Cthulhu or Arioch).
Marzanna - the goddess of Death, Winter and Nightmares.
Baba Yaga - goddess of Sorcery; not as evil as the other Lords of Chaos.
Blud - god of Madness and Debauchery.
Chort - Lord of Demons; Master of Possession.
Koschei - god of Undeath.
Poludnitsa - goddess of Summer and Madness; sometimes sacrifices are made to her to bring solace in the harsh winter.
Likho - the one-eyed goddes of Misfortune.
Tryasavitsa - goddess of Plagues and Illnesses.
Chaotic Cleric worships one of the Lords of Chaos and does his or her
utmost to spread Chaos in the world. The Evil Shrine of Chaos in B2:
Keep on the Borderlands is dedicated to Marzanna.