This book is related for the design and development of online educational games in language teaching and learning, particularly in learning Arabic language. The design and development of this online games prototype started with an analysis of learning theories relating to Vocabulary by Nation (2001), Multimedia Learning by Mayer (2001) and Digital Game-Based Learning by Prensky (2001). The ADDIE ID model has been chosen as ID model for research methods and procedures in five different phases of analysis, design, development, implementation and evaluation under the light of design and development research (DDR) by Richey and Klein (2007). The participants were purposively selected from 215 learners, 16 lecturers, 14 experts in instructional design (ID), Arabic subject matter expert (SME) and game-based learning (GBL). The mixed-method approach was employed in data collection such as descriptive quantitative survey, open-ended questionnaires, interviews, think aloud method, contentanalysis, field notes, class observation and testimonial. In general, this book contributes theoretically and practically in the design and development of an online Arabic vocabulary learning games.