Highlights: [•] We examined how multiple climate change drivers affect the grain quality of rice. [•] In addition to warming, elevated [CO2] deteriorated grain quality by increasing the number of immature chalky grains (ICGs). [•] Furthermore, warming and elevated [CO2] synergistically increased ICGs. [•] Extreme wet events (EWEs) further exacerbated the quality deterioration by elevated [CO2]. [•] Elevated [CO2] reduced grain protein content (PC), whereas EWEs increased the PC. [ABSTRACT FROM AUTHOR]