Today the majority of children and teenagers in many countries spend a great deal of time doing extramural English activities, where playing games is included. It is therefore important to study how extramural English activities affect students’ proficiency. This thesis aims to investigate how games as an extramural activity, and extramural English activities in general could benefit upper secondary EFL and ESL students’ English language proficiency. The method used was that of a systematic literature review where six studies from varying places and with participants of varying ages and levels of education were analyzed and compared. The results show that five of the articles found a positive correlation between time spent on extramural English activities and English grades and/or vocabulary, while on study showed that there was no correlation between time spent on extramural English activities and development of academic vocabulary in students who had already reached a high level of proficiency. More research is needed in the field, particularly studies establishing causation rather than just correlation, longitudinal studies, as well as studies investigating whether gender is an important factor affecting the potential benefits of extramural English activities.