Self-efficacious children are expected to be more task-focused in challenging achievement situations and consequently have better chances of overcoming learning difficulties than children who have lower self-efficacy. The present study investigates this presumption with Finnish-speaking first graders struggling with reading acquisition (N = 285). The development of the children's reading fluency, self-efficacy, and task avoidance was followed from the middle of Grade 1 to the end of Grade 2, and a 6-week mobile game-based intervention was administered to those who exhibited the greatest risk for reading disabilities ([less than or equal to] 5th percentile). Exploratory structural equation modeling was used to test the theoretical model. The results suggest that higher self-efficacy in the middle of Grade 1 predicted lower task avoidance and higher reading fluency at the end of Grade 1, but no support for the mediating role of task avoidance was found. The intervention benefited both self-efficacy and reading fluency.