We examined the effect of habitual regulation of massive multiplayer online role-playing game (MMORPG) playing on the problematic (addictive) usage and excessiveness of gaming (time that user spent playing weekly, per session, and in relation to his other leisure activities). We developed the approach to assess the strength of habitual regulation that was based on sensitivity to situational cues. We defined cues as real-life or in-game conditions (e.g., work to be done, activities with friends or family, need to relax, new game expansion) that usually promote gaming (proplay cues) or prevent it (contraplay cues). Using a sample of 377 MMORPG players, we analyzed relationships between variables through partial least squares path modeling. We found that proplay cues sensitivity significantly positively affected the excessiveness of gaming (playing time) as well as the occurrence of problematic usage symptoms. Conversely, contraplay cues sensitivity functioned as a protective factor from these conditions; significant negative effects were found for playing time and problematic usage. Playing time was confirmed to be a mediating variable, affected by cues sensitivity and at the same time affecting problematic usage symptoms. We obtained moderately strong coefficients of determination for both endogenous variables (R(2) = 0.28 for playing time; R(2) = 0.31 for problematic usage) suggesting that the proposed variables possess good explanatory power. Based on our results, we argue that the strength of habitual regulation within MMORPG usage has both positive and negative effects on excessive and problematic usage, which is a new and important finding within the area of Internet gaming addiction.