This paper suggested a conceptual model of user engagement for mobile based augmented reality (AR) games. Literature revealed the importance of user engagement for defining a successful technology application such as game. However, user engagement in particular is still not clearly studied for the mobile augmented reality games area. This paper critically reviewed the relations of user engagement elements in the mobile augmented reality game and guidelines that related to engagement for such type of games. It then recommended eight attributes of user engagement conceptual model for mobile based augmented reality games that can be used by game designer to design engaging mobile AR games for the industry and future AR engagement research.