Role

Victory in DotA 2 cannot be brought by a single person. It is won by the effort of the whole team. Team composition, therefore, is an extremely vital concept to grasp in order to win. A team in which all 5 hero fill in the same role will have more difficulty versus a team who balances out their team. There are few exceptions and deviations of this rule but these are much rarer. These occure mostly when teams have high skill discrepancies between them.

Basically, the three major roles are Ganker, Support and Carry. A single hero can commonly fill in two roles but there are a few that can fill in all three. The are also lesser, more subtle roles such as Pusher, Tank, Roamer, Jungler among others.