In the past five years systematic searches, serendipitous discoveries and archival searches have yielded over a dozen transients that are brighter than novæ but fainter than supernovæ. The observed properties of these “gap” transients tend to place them in distinct classes, some being about 100 times brighter than novæ and durations of nearly 100 days (e.g., M85 OT, PTF10fqs), while others (such as SN2002bj and PTF10bhp) nearly reach supernovæ luminosities but fade in five days. The state of theoretical understanding varies substantially across the class of objects, and is ripe for progress.