We consider metallic alloys of Cu*, Cu, and Cu** in which the atoms differ only in their atomic radii and examine how the size ratio affects the local orders in the alloy systems. These studies use molecular dynamics simulations in which the atomic interactions are modeled with a Sutton-Chen many-body potential. Considering rapid cooling of these binary and ternary alloys from the melt, we find three regimes defined by the magnitude of atomic size ratio lambda (lambdaless than or equal to1.0): with (i) large size ratios of 0.95