From the introduction:
Slayers is a tabletop RPG of monster hunters for hire. Known by locals as Slayers, players will wander a haunted city, cursed long ago to expand towards the horizon forever, with neighborhoods appearing and dissolving overnight. Slayers help clean out the monsters that infest the alleyways and shadows, and those that the city seems to be manifesting on its own. The world is just on the cusp of an industrial revolution, with new technology clashing with the arcane ways of old.
It's slay or be slain. Better get to work.
The goal of Slayers is to provide a rules-lite system for fast action, and exciting combat. In order to do this, the classes have been designed with asymmetry front and center. At its core, this game uses a resolution mechanic called the Rule of 4 for all actions, but how each class approaches this mechanic in combat is quite different.