Abstract Second language (L2) acquisition research emphasises the critical role of out-of-classroom (extramural) input in L2 development. Despite its popularity among L2 learners, the effectiveness of gaming on incidental L2 vocabulary development remains understudied. Thus, this exploratory study investigates whether vocabulary can be acquired from playing computer games and how learner-specific factors (L2-English vocabulary size, gaming habits, engagement) influence learning gains. Twenty-three intermediate English learners played a modified game featuring embedded nonwords in the written game text. Vocabulary knowledge was assessed at form-recall and meaning-recognition levels. An increase in vocabulary knowledge was found for both levels immediately after treatment, with considerable retention after one week. Gaming habits and engagement significantly predicted gains. Findings suggest gaming is an effective extramural activity for incidental L2 vocabulary development, offering important insights for L2 teaching and research.
Suprapas et al. (2026) studied this question.