Due to their motivational nature, there has been growing interest in the potential of games to help teach academic content and skills. This report examines how different levels of detail about a game's scoring rules affect math learning and performance. Data were collected from 164 students in the fourth to sixth grades at five after-school programs. The treatment conditions were randomly assigned within each setting and included a control group (played a different math game); three variations of scoring explanations (elaborated, minimal, and no scoring information); and combined elaborated scoring explanation with incentives to access additional feedback. The scoring explanation alone did not lead to better math learning. However, compared to the minimal-to-no scoring information variations, the combined treatment of the elaborated scoring explanation and incentive resulted in higher normalized change scores and, after controlling for pretest scores, higher posttest scores. Implications of the results identify attributes for learning games in mathematics. Appended are: (1) Sample Assessment Architecture ("Save Patch"); (2) Rational Number Knowledge Specifications; (3) Scored Event Rationale; (4) Example Tutorial Images: Stage 2; (5) Feedback Images; (6) Sample Additional Feedback; (7) Item Specifications (Sample); (8) Pretest Administered; (9) Administered Posttest; (10) Administered Post-Game Survey; (11) Rubric for Open-Ended Items; (12) Rationale for Intraclass Correlation Coefficient Model; (13) Descriptive Statistics for Background Variables; and (14) Correlation Matrix: Game Performance and Math Achievement Measures. (Contains 33 tables, 7 figures and 10 footnotes.) [This paper was supported under the Educational Research and Development Centers Program.]