Manufacturers of generic wargaming models are generally obliged to build their models to some standard scale so as to ensure compatibility with third-party wargames. Manufacturers who make proprietary models designed exclusively for use in a specific wargame do not have this concern. For instance, Warhammer 40,000 officially does not have a scale. It doesn't need to conform to a standard scale, because Games Workshop is the exclusive manufacturer of official Warhammer 40,000 models, said models are intended exclusively for use in Warhammer 40,000, and Games Workshop doesn't want players using foreign models from other manufacturers.