The study investigates the impact of Massively Multiplayer Online Role-Playing Game (MMORPG) on players' application of vocabulary learning strategies. The participants are experienced online gamers aged between 24 and 25 years old. Apart from identifying the vocabulary learning strategies used by the ESL players during online gaming, in order to find out how aspects related to MMORPG influence the use of strategies, data were also obtained from online semi-structured interviews with these (ESL) players who are involved in Guild Wars 2, a popular MMORPG computer game. Using Gu and Johnson's (1996) categorisation of vocabulary learning strategies (VLS), it was found that these ESL players utilise metacognitive, cognitive, memory and activation strategies in order to learn game-related vocabulary during the MMORPG game-play sessions. Additionally, there are four factors that affect the vocabulary language learning experience of the players, and they consist of; (a) the role of game storylines in enhancing MMORPG gaming immersion, (b) freedom to learn while being away from classroom-related rules, (c) social interaction that enriches players' learning experience, and (d) the role of collaboration among the MMORPG community in enriching learning experience.