After an exceptionally swift reform movement in the 1990s, 15 states are now adjusting to the most significant institutional change to their governments in a generationlegislative term limits. Beyond the basic task of identifying and cataloguing their various substantive impacts, term limits have presented scholars with an exceptional opportunity to test legislative theory for two reasons. First, most legislative theory is based on behavioral assumptions that term limits appear to affect systematically, such as the reelection motivation. Second, the distribution of term limits across the states gives scholars exceptional methodological advantages for testing theory. In this article, I review the scholarly literature on the impacts of state legislative term limits, describe their theoretically relevant implications and methodological advantages, and advocate using the reform to develop an important research agenda.u.s. state legislative term limits are a once-in-a-generation endowment to scholars of American-style, bicameral, transformative legislatures. As "the most significant change to the legislative institution since the modernization movement of the 1960s and 1970s" (Moen, Palmer, and Powell 2005, 2), the evaluation of the reform's substantive effects has kept certain scholars busy for the past decade and a half. 1 Term limits have been shown or hypothesized to have an extraordinarily wide range of impacts, including effects on:• candidate decisionmaking (