Understanding the human respiratory system, particularly the microscopic processes of gas exchange, is challenging for junior high students transitioning from concrete to abstract thinking, often leading to rote memorization. This study examines the effect of tour games tournament (TGT) battle, a board game integrating TGT that simulates O₂ and CO₂ diffusion, on conceptual understanding. It describes student mastery profiles across Bloom’s cognitive levels. A quasi-experimental pretest-posttest control group design was employed with 48 eighth-grade students (24 per group). Conceptual understanding was measured using a validated 30-item multiple-choice test, analyzed via paired/independent t‑tests, effect sizes (Cohen’s d), and descriptive indicator profiling. Results showed TGT battle significantly outperformed conventional instruction, with experimental posttest (M=14.71) and gain scores (M=5.33) far exceeding controls (M=10.88; M=0.92; p<0.001; d=1.65–1.66), demonstrating large practical effects. Gain distributions confirmed consistent improvement across all ability levels and effectively prevented the reinforcement of misconceptions. Bloom's profiling revealed the highest mastery at the understanding level (C2, Indicator 1=0.75) and strong higher-order thinking (C4–C5, Indicators 10–12=0.68). However, a critical weakness emerged at the application level (C3, Indicator 5=0.46), attributable to the game's linear design, which fragmented internal and external respiration. TGT battle effectively builds foundational and higher-order understanding, yet requires structured post-game debriefing to bridge gaps in intermediate application. Thus, it serves as a robust, inclusive instructional strategy for abstract secondary biology when complemented by reflective conceptualization phases.