The scanning limitations of rms-responding liquid-crystal devices as influenced by device characteristics, the type of matrix addressing scheme, and waveform tolerances are quantified in this paper. An rms selection scheme that yields a greater number of scanned lines than a 3:1 selection scheme is presented and analyzed, together with a two-frequency addressing scheme that overcomes limitations on scanning associated with the cutoff frequency for dynamic-scattering. Dynamic-scattering liquid-crystal displays are the main emphasis of this paper. However, many of the results apply to field-effect liquid-crystal displays. Copyright © 1974 by The Institute of Electrical and Electronics Engineers, Inc.