Ə or SCHWA stands for Sorcerer Character Has Warrior Adventure.
Preamble inside book:
Have you ever played a Barbarian or taken proficiency in the Awl Pike just to be able to use your 12-sided die? Do look wistfully at your 24- and 30-siders and dream of rolls that haven't come? Do you play a spell-caster, no matter how much you dislike the class, just for the opportunity to roll a handful of six-siders at higher levels? Or jumped your character off a cliff on the promise that you could roll your own damage? If any of these questions sound completely reasonable then Sorcerer Character Has Warrior Adventure might be the game for you.
Sorcerer Character Has Warrior Adventure, or Ə, uses dice. A lot of dice. The sizes of the dice are arranged into eleven Ranks.