There is a growing focus on examining how the order of tasks impacts oral and written output in a second language, particularly concerning syntactic complexity, accuracy, lexical complexity, and fluency (CALF). Despite previous studies, the findings have been inconsistent. This research synthesis and meta‐analysis, centered around Robinson's (2010) SSARC model of pedagogical task sequencing, aims to: firstly, analyze the types of tasks used in investigating task sequencing and its effects on L2 production; secondly, explore the definitions of task complexity and task sequence in research on task sequencing and its impacts on L2 production; thirdly, examine the metrics of CALF in the study of task sequence and its effect on L2 production; and finally, assess the effects of task sequence on CALF in L2 production. The results show consistencies in Second Language Acquisition (SLA) research regarding the manipulation of task sequencing, particularly the progression from simple to complex tasks using features that direct or disperse cognitive resources. Our findings demonstrate positive effects for the sequence of tasks from simple to complex on syntactic complexity and accuracy of L2 production, regardless of the mode of production. In contrast, random task sequencing primarily impacts the accuracy of L2 production, particularly in oral production.