The RX-78-3 G-3 Gundam is a fictional prototype mobile suit from the Mobile Suit Variations (MSV) line in the Gundam franchise. It is an alternate test version of the original RX-78 Gundam, distinguished by its gray color scheme and experimental nature. The unit is often portrayed as a high-performance development machine used for testing advanced systems and combat potential. It represents an important step in the evolution of the Gundam design and appears as a notable variant in side materials and model kit lore.