This paper proposes the identification and use of principle-based pedagogical patterns to help teachers to translate design principles into actionable teaching activities, and to scaffold student learning with sufficient flexibility and creativity. A set of pedagogical patterns for networked Second language (L2) learning, categorized and undergirded by rapid collaborative knowledge improvement (RCKI) principles, has been extracted and articulated in our school-based research. The patterns are distilled from a series of over 60 Chinese language lessons conducted in real classrooms which are co-designed by teachers and researchers over a 3-year period in Singapore schools. Each principle-based pedagogical pattern is presented succinctly in a simple pattern language. Two classroom scenarios of collaborative activities are elucidated, embodying some of the patterns to provide a more grounded feel of how they are enacted in practice. RCKI principle-based pedagogical patterns inform the design of collaborative language learning activities in networked classrooms. Preliminary findings reveal that principle-based pedagogical patterns provide teachers a workable way to design RCKI activities and enable teachers to adopt, internalize and adapt them in classroom use. (Contains 1 table and 7 figures.)