Dungeons and Dragons (video game)/YMMV

Shadow Over Mystara

 * Evil Is Sexy -- Synn in human form.
 * Game Breaker: You can get equipment bonuses based on special combination of letters used in the "Name Your Character" screen. There are entire faqs based around using gibberish names to completely twink-out characters before you even start the game, although most of this crosses into Good Bad Bugs territory and was in fact a reason many arcade owners ended up removing the game entirely, as the use of the gibberish names often had the side effect of crashing or severely glitching out the graphics of the game, making the arcade owners think there was something wrong with it and thus making this double as a literal Game Breaker. Plus, beating the game on a single credit because you're practically (and in case of one of the bugs, functionally) invincible doesn't make for a very profitable cabinet. The glitchy names were later fixed with an updated version of the game, although by that point the damage was more or less done.
 * Large Burning Oils are a more conventional way to break the game: with a large enough supply of them, most bosses can be knocked down in any way you please, and then kept in a stunlock until their HP runs out by dumping enough LBOs on their prone bodies.
 * Player Punch: In Tower of Doom, you have to choose between going to Fort Cruth or hurrying on to get gelp. If you do the latter, Fort Cruth is wiped out. If you do the former, you meet a merchant whose daughter, whom you rescued on the other path, goes missing and is never seen again.
 * That One Boss: Dragons, particularly the red ones as the Bonus Boss for both games and the Final Boss for the first game