We describe a simple and cost-effective concept for implementing a Ground Layer Adaptive Optics (GLAO) system on Gemini that will feed all instruments mounted at the Cassegrain focus. The design concept can provide a GLAO correction to any of the current or future seeing-limited optical or near-infrared Gemini instruments. The GLAO design uses an adaptive secondary mirror and provides a significant upgrade to the current telescope acquisition-and-guide system while reusing and building upon the existing telescope facilities and infrastructure. This paper discusses the overall design of the GLAO system including optics, opto-mechanics, laser guide star facilities, natural and laser guide stars wavefront sensors. Such a GLAO system will improve the efficiency of essentially all observations with Gemini and also will help with scheduling since it virtually eliminates poor seeing.