  The blossoming field of joint gravitational wave and electromagnetic (GW-EM)
astronomy is one of the most promising in astronomy. The first, and only, joint
GW-EM event GW170817 provided remarkable science returns that still continue to
this day. Continued growth in this field requires increasing the sample size of
joint GW-EM detections. In this white paper, we outline the case for using some
percentage of LSST survey time for dedicated target-of-opportunity follow up of
GW triggers in order to efficiently and rapidly identify optical counterparts.
We show that the timeline for the LSST science survey is well matched to the
planned improvements to ground based GW detectors in the next decade. LSST will
become particularly crucial in the later half of the 2020s as more and more
distant GW sources are detected. Lastly, we highlight some of the key science
goals that can be addressed by a large sample of joint GW-EM detections.
