This quasi-experimental study investigated the effects of enhancing digital game-based science learning with the predict-observe-explain (POE) inquiry scaffolds. One hundred twenty seventh-grade students were assigned to either an experimental group or a control group. The two groups of students played the same game, but the experimental group additionally followed a POE inquiry guide in the gameplay. Students' in-game performance and inquiry behaviors were examined along with their conceptual understanding of the physics concepts addressed in the game. The findings suggested that the group that followed the POE guide performed significantly better in both conceptual understanding and game performance. The analysis of the two groups' inquiry behavioral data revealed different learning pathways, which shed light on how the inquiry scaffolds helped students in GBL. The article ends with practical implications for implementing game-based science learning.