I will give you a brief introduction to the conceptual design for the Wide Field Optical Spectrograph that will be one of the three first light instruments for TMT. This version of WFOS is being designed at UCSC/UCO-Lick and is called MOBIE, which stands for Multi-Object Broad Band Imaging Echellette. It is designed with the primary goal of satisfying as broad a range of observers and science goals as possible, from low resolution spectroscopy with maximum multiplexing, to moderate resolution (R~8000) with moderate multiplexing. The echellette format is enormously flexible; it allow the observer to optimize wavelength coverage, slit length, and multiplexing as they choose, while still minimizing the mechanical complexity of the instrument. This is your first peek at the optical workhorse spectrograph for TMT.