The basic gist of the game is simple. Score points. Don't let your opponent do the same. It may seem like it is just players playing, however every play is coldly calculated and every action has been practiced endlessly. Teams have extensive playbooks designed to fit their player's talents.
Before teams take the field, they have studied each other to great lengths. At the professional and collegiate level, teams have frequent meetings during the week to study and prepare for the weekend's game.