The ability to dominate conspecifics and thereby gain access to resources depends on a number of traits and skills. Experience of dominance relationships during development is a potential source of learning such skills. We here study the importance of social experience, aggressiveness, and morphological traits for competitiveness in social interactions (winning duels) in male domestic fowl (Gallus gallus domesticus). We let males grow up either as a single (dominant) male or as an intermediately ranked male in a group of males, and measured their success in duels against different opponents. We found that single-raised males had lower competitive ability than group-raised males, and that aggression and comb size had positive effects on competitive ability. This indicates that experience of dominance interactions increases future success in duels. We similarly studied the consequences of growing up as a dominant or subordinate in a pair of males, finding no statistically significant effect of the dominance position on competitive ability. Finally, we found that males were consistent over time in competitive ability. We conclude that social experience increases competitive ability in male domestic fowl, but that certain behavioural and morphological characteristics have an equal or even stronger influence on duel outcomes.