The UTX file format is a proprietary archive format primarily used by the Unreal Engine, specifically versions 1 and 2 (Unreal Engine 1 and 2). These files act as container packages that store texture assets, including diffuse maps, normal maps, and other graphical data required for rendering 3D environments and character models. In the context of classic games like Unreal Tournament, Unreal, and Deus Ex, UTX files were essential for bundling multiple textures into a single file to optimize memory usage and loading times. Because these files are binary archives, they cannot be opened by standard image viewers; they require specialized Unreal Engine tools or game-specific editors to extract the individual texture data, which is typically stored in formats like PCX or TGA internally. While modern versions of the Unreal Engine have moved toward different asset management systems like .uasset, the UTX format remains a significant piece of gaming history for modders and developers working with legacy titles.