The purpose of this study was to examine the effect of integrating self-explanation principles  into a digital game-based environment on the students' acquisition of light and shadow concepts. 35 third graders were recruited and randomly assigned to either an experimental group or a control group. 16 students in the experimental group were required to play a game with self-explanation prompts, where 19 students in the control group played a game without any prompts. Students' conceptual understanding was evaluated through a pretest, and a posttest that occurred right after the treatment. The results revealed that in terms of the posttest, students who played the game with self-explanation features did not outperform those who played the game without any prompt. But, when comparing their improvement from the pretest, it was merely the students in the experimental group whose posttest scores were significantly higher than their pretest scores.