| | | | Part I |
| 1 | Samson | Mazer | Protagonist. A game developer. Aka: S.A.M, Sam Masur. |
| | Marx | Watanabe | Sam's roommate. |
| | Sadie | Miranda-Green | Sam's old friend. |
| | Anna | Lee | Sam's mother. |
| | Steven | Green | Sadie's father. |
| | Sharyn | Friedman-Green | Sadie's mother. |
| | Anders | Larsson | Sam's math adviser. |
| | Ajda | | Marx's latest girlfriend. |
| 2 | Alice | Green | Sadie's older sister. |
| | Dong | Hyun | Sam's grandfather. Anna's father. |
| | Bong | Cha-Lee | Sam's grandmother. Anna's mother. |
| | Freda | | Sadie's grandmother. |
| 3 | Dov | Mizrah | The Advanced Games Seminar professor. Sadie's first boyfriend. |
| | Hanna | Levin | The only girl in the seminar. |
| | Florian | | One of the students in the seminar. |
| | Dr. | Tybalt | Sam's doctor. |
| | Batia | Mizrah | Dov's wife. |
| | | | Part II |
| 1 | Ryu | Watanabe | Marx's father. |
| | Kotaku | | The game reporter who interviewed Sam. |
| | Mary Lou | Retton | An American gymnast. |
| 2 | George | Masur | Sam's father. |
| | Miss | Elliot | George's assistant. |
| 4 | Chris | Cornell | An American singer. |
| | Zoe | Cadogan | Sam's music designer. Marx's girlfriend. |
| | Max | Matsumoto | A football player. |
| 6 | Tiny | Tim | The hurt boy. |
| | Keanu | | The Asian boy. |
| | Audrey | | The pretty brunette girl. |
| | Telemachus | Mizrah | Dov's son. Aka: Telly. |
| | | | Part III |
| 2 | Jonas | Lippman | The CEO of Cellar Door. |
| | Aaron | Opus | The head of OPUS computers. |
| | Ichigo | | Sam and Sadie's lead character in their game. |
| 3 | Hanami | | Ichigo's little sister. |
| 5 | Chip | Willingham | A movie actor. |
| | Anne | Chin | Chip's former leading lady. |
| | | | Part IV |
| 3H | Abe | Rocket | Sadie's boyfriend. A band lead singer. |
| 4A | Lola | Maldonado | Sam's former schoolmate. |
| 5A | Simon | Freeman | A Junior at CalArts. Marx's game developer. |
| | Antonio | Ruiz | Marx's game developer. Simon's lover. Aka: Ant. |
| | | | Part V |
| 2 | Thomas | Andrews Jr. | A naval architect. |
| | Aeran | Watanabe | Marx's mother. |
| | Midori | | Marx's high school best friend. |
| | Swan | | Marx's high school best friend. |
| 3 | Albert | | Sam's cousin. |
| | | | Part VI |
| 1 | Mayor | Mazer | Sam's avatar. |
| 4 | Christopher | Marlowe | The man who was murdered in Master of Revels. |
| | | | Part VII |
| | Charlotte | Worth | A game designer Marx met. |
| | Adam | Worth | Charlotte's husband. |
| | | | Part VIII |
| 3 | Mori | | One of Sadie's workers. |
| 4 | Naomi | Watanabe-Green | Sadie and Marx's daughter. |
| | | | Part IX |
| | Emily | Marks | Sadie's game name. |
| | Alabaster | Brown | The vintner. Emily's neighbor. |
| | Dr. Edna | Daedakys | The optometrist. Sam's game name. |
| | Pixel | | Emily's horse. |
| | Ludo Quintus | Marks-Daedalus | Emily's son. |
| | | | Part X |
| 1 | Harry | | One of Sadie's students. |
| | Destiny | | One of Sadie's students. |
| | Jojo | | One of Sadie's students. |
| | Rob | | One of Sadie's students. |
| 4 | Marie | | The Revejeux team leader. |
