Careers are often seen as the main antagonists of the Hunger Games due to their exceptional skills and ruthless determination to win. They often form alliances with each other for mutual protection and strategy during the Games. They can recognize other tributes of the games due to certain signs of training at young ages such as muscle definition.
While careers have certain advantages of training, the gamemakers often find their training as one factor when designing arenas and obstacles with the intention of evening the fight and increasing viewers' entertainment.
Katniss Everdeen and Johanna Mason from District 13 are examples of tributes who challenged the dominance of careers to various degrees of success