The idiom "循规蹈矩" is formed through a classic parallel structure common in Chinese, where two near-synonymous compounds reinforce the same core idea. The first half, "循规" (xún guī), means "to follow the compass," and the second half, "蹈矩" (dǎo jǔ), means "to tread according to the carpenter's square." Here, "规" and "矩" are ancient tools for drawing circles and squares, respectively, serving as metaphors for rules, standards, and proper conduct. By pairing the verbs "循" (to follow) and "蹈" (to tread on/abide by) with these symbolic nouns, the idiom creates a powerful, rhythmic expression that emphasizes strict adherence to established norms, customs, or regulations.