The word "规则" is formed by combining two characters, each with its own concrete historical metaphor that together create an abstract concept. "规" originally depicted a compass used for drawing circles, symbolizing measurement, standard, and correctness. "则" was based on the idea of inscribing laws or standards onto bronze vessels using ancient shell currency ("贝") and a knife ("刂") as a metaphor for fixed, engraved principles. Thus, the compound "规则" visually and conceptually merges the imagery of a tool for precise measurement ("规") with the idea of an inscribed, unchanging law ("则") to represent the modern meaning of "rules" or "regulations".