In order to better facilitate scaling up of classroom innovations, two complementary strategies have often been discussed. The "community-based strategy" emphasizes the necessity for professional learning communities and their embedding in institutional settings. The "material-based strategy" starts from well-designed teaching materials, which are considered catalysts for bringing teaching approaches to many classrooms. The implementation project reported on in this study systematically combines both strategies and takes a third strategy into account: the systemic strategy of addressing higher levels of the school system, such as the school and district levels. The goal of the project is to help teachers to better support low-achieving students at the beginning of German secondary schools (grades 5 and 6). The results of the accompanying research in a quasi-experimental study, reported in this article, show that a combination of strategies can be effective: the participating low-achieving students had higher learning gains than a control group did. The deeper analysis provides insights into the complexities of the interplay of community aspects, institutional backgrounds, and the power of substantial teaching materials.