NCAA College Football 2K3 features a complete roster of 117 Division I-A schools as players attempt to guide their team to one of the 25 bowl games. Player models have been designed to reflect the true size of college athletes as compared to NFL players, and a Heisman Trophy race has been incorporated to honor the top performer of the year. The highlight of the game is the Legacy Mode, in which players can custom build their own athletic program and then manage their school over the course of 25 seasons. The game is endorsed by 2001 Heisman Trophy-winner Eric Crouch, who also contributed to some of the play design, moves, and audio featured on the disc.
In addition to the Legacy Mode, players can register for a Practice, Tourney, Exhibition, and Season, or create their own Division I-A school and player lineup. Practice involves choosing from different formations and plays to learn more about the team, develop a sense of timing, and familiarize themselves with the controls. Tourney offers a choice of four, eight, or sixteen teams, while Exhibition is simply a match-up between two schools in a single game. Season has players embarking on a series of conference and non-conference games while trying to earn the respect of the Sega Championship poll. By achieving a first or second ranking, players will be invited to the Fiesta Bowl for the championship.
Legacy Mode sees the championship rotating between the following four bowls: Fiesta, Sugar Bowl, Orange Bowl, and the Rose Bowl. In between seasons, players will be able to see how they fared in a Coaching Comparison screen before they begin the five-week process of recruiting new players from high schools and junior colleges. Unique to NCAA College Football 2K3 is the ability to develop the team through training exercises. Players can spend training points on such drills as rollouts, grip strength, conditioning, routes, and tackling to improve their team's overall abilities before the season begins. Yet players run the risk of injury or having their other ratings diminished if they train too much in one area, so points must be spent wisely.