The aim of this study was to determine the effects of different types of language tasks performed in Second Life (SL) on the oral performance of beginners of Chinese as a Second Language (CSL), focusing on oral accuracy. The 30 CSL beginners who participated in this study were randomly divided into two groups (n = 15 per group), required to perform two different types of language tasks: information-gap and reasoning-gap. During the study, both the Mandarin oral accuracy and the learning motivation of both groups were measured and analyzed to determine to what extent performing the two different task types could contribute to the two dependent variables (i.e., accuracy and motivation). All the learners improved significantly in oral communication competence, with those performing the reasoning-gap task improving significantly more than those performing the information-gap task. It was also found that almost all the learners exhibited positive learning motivation and appreciated the task-based learning activities designed in SL. Both groups made significant improvement in the affective dimension. Furthermore, the reasoning-gap group received significantly higher scores in the educational-context-related dimension (attitude toward SL as the Mandarin Chinese learning environment) than the information-gap group did.