Gundam SD (Super-Deformed) grades are a line of chibi-style, compact Gunpla (Gundam plastic models) known for their cute, exaggerated proportions, often built by beginners due to simplicity, but now featuring high-end releases like the MGSD (Master Grade SD) line that integrates Master Grade inner frames, superior articulation, and detailed gimmicks into the small format, bridging the gap between simple SD kits and complex standard grades.