Using Nicholls’ developmental component as a framework, the purpose of this study was to examine children’s understanding of luck and ability in the physical domain. Children (N = 144, 8 boys and 8 girls at each age from 5 to 13 years) enrolled in public schools participated individually in a 30-min session in which they were shown 2 similar games; one required luck and the other required skill to perform successfully. Participants received an explanation of the games and were told of youngsters who had tried unsuccessfully to play them. Participants were interviewed, and their responses were analyzed via a Piagetian structural developmental method. Results revealed that the 4 levels of understanding of luck and ability Nicholls and Miller (1985) described were relevant to the physical domain. Furthermore, the Spearman rho coefficient indicated a strong positive relationship between children’s age and their level of understanding of luck and ability.