In 'The Hunger Games', Seneca Crane is the Head Gamemaker for the 74th Hunger Games.
As Head Gamemaker, Crane oversees the arena's hazards, engineered events, and the televised presentation designed to entertain the Capitol. He is responsible for turning the Games into a tightly controlled spectacle, using elements such as fireballs, tracker jackers, muttations, and the final rule change that appears to allow two victors from the same district.
That rule is introduced to encourage Katniss Everdeen and Peeta Mellark to cooperate, but their decision to threaten suicide with nightlock berries exposes the Capitol's loss of control. President Snow blames Crane for the political embarrassment. In the novel, Snow later tells Katniss that Crane was executed; the 2012 film depicts him being locked in a room with poisonous nightlock berries.
Seneca Crane is often confused with Plutarch Heavensbee, who becomes Head Gamemaker for the 75th Hunger Games and secretly works against the Capitol. Haymitch is a former victor and Katniss's mentor, while Katniss is a tribute, not a Gamemaker. Wes Bentley played Crane in the film adaptation.