Main character is John Rico. He is the protagonist and he is a round and dynamic character. Some personality traits are kind, dedicated to his friends and the infantry, and brave because he joined the mobile infantry.
Carl is another character he is friends with John in high school but is shipped off three days before John. He is a flat character. He doesn't play a huge role in the story.
Carmen is John's friend as well. She is a flat character.
Sergeant Zim is John's sergeant at camp Arthur Currie. He is a round character. His personality traits are determined, mean, and strict.