The Arithmancers, known as well as Numbermancers, was a caste of Goblins mathematicians that allegedly by their study of numbers got a higher understanding of the contstucts of reality.
However, their mathematical works and discoveries often where discarded by other mathematicians, because of the use of drugs in their theoretical process, saying the critics that -as Daemor of Ria:
"The Arithmancers are just a bunch of goblins in fancy hats that get stoned all day, writing down gibberish to justify the gold they get from their king"
The claims of understanding of the world throught numbers was beyond the physical world and boundaries, but down to a spiritual plane.
Other goblins, not understanding the numbers, but considering them truth, held the numbers discovered by the Arithmancers as sacred or divine.
The Arithmancers are said to be the ones responsible for some innovative tactics, and numbers as Threish -they claim they discovered before the creation of the nation of Threish, who stole their name, and that they would go for war for it, but they were too high to care- and Elevenity.