The characters combine in a very direct and literal way: “Using an egg (卵) to strike (击) a stone (石).” The metaphor is immediately understood, painting a clear picture of a self-destructive and pointless endeavor.
The origin of this idiom is often traced back to the philosopher Mozi (墨子, c. 470-391 BCE). When advising against a small state's plan to attack a much larger, powerful state, he argued that it would be like “using the eggs of the entire world to strike a stone”—no matter how many eggs you use, the stone will remain unbroken. This idiom highlights a strong undercurrent of pragmatism and strategic thinking in Chinese culture. While Western culture has heroic tales like “David and Goliath,” which celebrate the underdog's triumph against all odds, 以卵击石 carries the opposite connotation.
以卵击石 is a common idiom used in both formal writing and everyday conversation to criticize a course of action that is clearly doomed to fail.