This quasi-experimental survey involves 100 participants aged 18-24 years, conducted to measure effects of advertising schema congruity in a massively multiplayer online role-playing game (MMORPG) and other aspects of gameplay experience. Results from a posttest questionnaire suggest that though moderately incongruent advertising in an MMORPG can trigger high awareness rates, extremely incongruent in-game advertising can reduce a game's perceived sense of realism and annoy players if not coordinated appropriately with the game environment. Whereas previous research suggests players usually accept in-game advertising when relevant, this study shows that the opposite occurs when advertisers fail to contextualize ads within the game world.