Magic in the world of Bas-Lag is omnipresent. Everyone knows about it and knows someone who has used it. However - skills in the field of magic are rare. While there may be 1 in 10 people capable of minor magics, the more skilled and more powerful occur 1 in 1000 or even less frequently.

Magic is Bas-Lag, like much of life in general, comes at a cost. Puissance (the power for a magic) must come from a source. Either the stamina and blood of the casting mage, the sacrifice of others, or chymical and thaumaturgic batteries constructed for the purpose.

Magic can come from the Gods as well - but the Gods must be bargained with and magic must be bought. For example, in the case of the monks of the Moment of the Hidden and the Secret - a Teshian order that worship the god Tekke Vogu have the powers to find hidden pathways (teleport of a kind), to remain unseen and to learn secrets. For each use they must have something of theirs hidden - they forget a memory, or have a skill removed, lose their native language or have a body part taken away, hidden forever by Tekke Vogu.

The water magic of Vodyanoi. All Vodyanoi seem to possess the power to shape water like clay, which it retains up to an hour. Shamans, however are able to summon Undine as well - a water elemental

The magic of the Gryndylow - probably unable to be converted to Hero. The Grindylow have such an alien view of the world that they should always be NPCs. The Grindylow specialise in dimensional magics, and have rather strange versions of offensive and transport spells at the very least (shown in The Scar).

Able to contact Hell. In New Crobuzon, you usually don't summon Demons, you tend to go to Hell and negotiate. Practicing Karcism makes you a Karcist. The mayor of New Crobuzon (Bentham Rudgutter) has an ambassador from Hell in one of the rooms at Perdido Street Station

Able to communicate over vast distances with psychometry. A female of this art is called a communicatrix.

Mixing technology and constructs with magic. All magic is classed as part of thaumaturgy. Fetishes/props/foci for Thaumaturgy often include chymical batteries, charms, animal parts, and clockwork devices.

The animation and creation of Golem. From simple clay up to shadow and sound golems.

Mixing technology and biology. Most biothaumaturges work in the Punishment Factories creating Remade from criminals.

Mind control through suggestion and whispers. Powerful Sussurators (or Wordsmiths) can whisper to a specific target over miles.

Manipulation and sensing of the earth. Turning rock to mud, detecting Smokestone eruptions or finding types of rock.

Elementarii summon elemental spirits which behave similarly to wild animals and must be tamed. The correct element for the Elementalist's particular specialisation (all elementarii must specialise in one element only) must be present for the summoning. A torch can be used for fire elementals, a herd of horses for flesh elementals.