Passion represents one of the factors involved in online video gaming. However, it remains unclear how passion affects the way gamers are involved in massively multiplayer online role-playing games (MMORPGs). The objective of the present study was to analyze the relationships between passions and motivations for online game playing. A total of 410 MMORPG players completed an online questionnaire including motives for gaming and the Passion Scale. Results indicated that passionate gamers were interested in relating with others through the game and exhibited a high degree of interest in discovery of the game, gaining leadership and prestige but little interest in escape from reality. However, some differences were observed with respect to the role of the two types of passion in the different types of motivation. Specifically, harmonious passion (HP) predicted higher levels of exploration, socialization, and achievement, in that order, while obsessive passion (OP) predicted higher levels of dissociation, achievement, and socialization. The present findings suggest that HP and OP predict different ways of engaging in MMORPGs and confirm that passion is a useful construct to help understand different motivational patterns demonstrated by MMORPG players.