In Super Smash Brothers Mêlée (SSBM), there are tens of characters in the roster to play as. Some characters have move-sets that are very similar to each other, but with different effects. These characters are often called "clones" in reference to each other. Marth and Roy are from the Fire Emblem franchise and act similarly, but I hardly see Roy in competitive play. What puts Marth above Roy in popularity? How are these characters distinct from one another?
While Marth and Roy have essentially identical animations, basically none of their moves are the same. The majority of Marth's attacks deal more damage when the tip of his sword hits, while by contrast the tip of Roy's sword is ridicuously weak.
I'm not a competitive player, but this alone is probably one of the reasons the Marth is better in tournaments than Roy. Marth is rewarded for staying in the zone where his attacks can just barely reach the opponent, where tourney-goers love to be since it puts you as far from danger as possible while still hitting. By contrast, Roy is punished for being in this zone, so he has to get in there and open himself up to more attacks.