Multidistrict litigation (MDL) is exploding. MDL makes up a large and increasing portion of the federal civil docket. It has been used in recent years to manage and resolve some of our largest controversies: opioids, NFL concussions, Volkswagen “clean” diesel, and many more. And, given its growing importance, MDL has come to dominate the academic literature on complex litigation. At its base, MDL is a tool to coordinate related cases across different courts in service of justice, efficiency, and fairness. These goals are not unique to the federal courts. State courts handle far more cases than federal courts, including the kinds of complex disputes that could benefit from coordination. Yet state MDL procedures are virtually absent from the scholarly literature. This Article offers a systematic study of state MDLs. Surveying the laws of every state, we find that about half the states have developed their own MDL-like procedural devices. What makes MDL distinctive is that it allows some official or institution to consolidate cases and to assign them to a handpicked judge. Therefore, we develop in this Article the first taxonomy of state MDL mechanisms based on which officials or institutions are given this substantial power. Along the way, we explore the other ways that states have tailored their MDL rules. We also provide case studies of three state MDL systems and report previously unpublished data on how state MDLs work. Building on these findings, this Article offers an institutional analysis of state MDL. We find that state MDLs distribute important cases to courts and judges in ways that depart dramatically from the default rules of judicial administration. These choices have important consequences for litigant control, judicial power, and both inter- and intrastate relations, which can be amplified in states where judges are elected. In these ways, different types of state MDLs—sometimes unwittingly—may tilt the usual balance in favor of plaintiffs or defendants, local actors or statewide ones, and voters or government officials.