Forgotten Realms/YMMV


 * Broken Base - Those who like the 4e Forgotten Realms as opposed to those who don't. Or vice versa depending on your point of view.
 * Base Breaker: Mystra. God all mighty, Mystra. There are two schools of thought on her; those who believe that she is the Realms, and those that believe she is everything wrong with the realms. On of the most popular questions asked post 4e is when will she come back? The two most popular answers are "In my game she never died " and "Hopefully never. " Interestingly, both sides generally agree that bringing her back would be a bad thing; those who were against her death have either given up on the setting already or treat it as discontinuity in their home games, and those who are for her death will have similar reactions to her being brought back.
 * Drizzt. Also, Drow PCs in general.
 * The Spellplague as a whole is yet another Base Breaker.
 * Complete Monster - Cyric.
 * Errtu also deserves mention.
 * As always, the Demon Lords, with special mentions going out to Lolth, Orcus, Demogorgon, Graz'zt, Yeenoghu and Pazuzu.
 * Continuity Porn - To be expected from a setting as vast, old, and collaborative as this one.
 * Evil Is Cool - The Shadovar, the Drow...
 * Evil Is Sexy: Asmodeus is described as being the most handsome of all devils.
 * Beshaba also counts.
 * Originally averted with Lolth. Her original form after being cast down by Corellon was that of a bloated, hideous spider with an elf's head. After the drow started to become a popular source of Evil Is Cool, she got changed into this.
 * Fandom Rivalry: With fans of Eberron.
 * Fanon - Discussions and interpretations taking place on the Forgotten Realms sections of the Official Wizards of the Coast D&D Messageboards
 * Fanon Discontinuity - Many fans choose to ignore the developments in 4E, mostly on the grounds that the 4E setting is less an update and more a new setting.
 * Game Breaker - Some consider various high-level NPCs to be Game Breakers.
 * Internet Backdraft - Edition War discussions and debates.
 * Ruined FOREVER - The Spellplague "messing up" Faerûn.
 * Also in the literal sense, as detailed locations ended up getting completely wiped out.
 * Fan Dumb - Nothing too big, but The Dark Elf Trilogy has a bothersome side-effect. Some overenthusiastic fans turned Drizzt into the icon of Overused Copycat Character, mistook Realms for a land ten times more High Fantasy than Krynn, made other Realms fans peery about suggestions that Lloth may be behind something and eventually had R.A.Salvatore himself write "This will sound strange, I know, but I'm almost a bit saddened by the success of Drizzt...".
 * Magnificent Bastard - Elaith "The Serpent" Craulnober, Jarlaxle, Lauzoril, Gromph Baenre...
 * Shadow dragon Aurgloroasa "The Sibilant Shade". Loves raiding in a shape of some rival dragon, who then receives dragonslayers. Spied upon a dwarven city 12 years before using their high priest as a puppet next 33 years and in 20 next years built with dwarven hands the temple, then got it consecrated to her deity (she's a priestess of dragon death god) and killed everyone in the city. Later she goaded the Cult of the Dragon to "find" and "seduce" her with riches exorbitant even by their standarts, only to get the ceremony subverted and turn into dracolich without their usual controls.
 * Cyric. Cyrinishad debacle, Trial of Cyric, Mystra's death, Helm's death, Tyr's eventual death, Kezef's freedom, the Spellplague...Yeah. Bastard indeed.
 * Moral Event Horizon: Jarlaxle manipulated events to start a war over the port of Luskan. After the fighting was over, with tons of citizens dead and the city partially destroyed, he made sure that food was scarce by preventing the flow of supplies into the city, and starved the people of Luskan until they were ready to rebel against the new establishment and install Jarlaxle's associate as the next ruler. As Affably Evil as he may be, it's difficult to forgive him for this. The fact that one of the people whose death he causes is  does not make it any easier.
 * Then again, it's Luskan. A major pirate nest and power base of both Arcane Brotherhood and Kraken Society. Not quite Zhentil Keep, but not very far from this.
 * The death toll from the initial war was stated at 4000, with hundreds more dying from the elements after the fact. It's explicit that a good portion of these deaths are civilians and children caught in the crossfire.
 * Worth mentioning is that this isn't treated as a Moral Event Horizon in the actual book. Jarlaxle skates by, suffering no real consequences for it. He's called out by Drizzt, but more specifically for the death of his friend  as opposed to thousands of others that died during the conflict. The kicker? Jarlaxle lies to Drizzt, saying he didn't arrange any of it, just that he hopes to take advantage of the situation. Drizzt drops it, and while it isn't made clear whether or not he believes Jarlaxle, what is clear is that many of the fans  do. 
 * The Woobie - Shandril Shessair. When training as a Person of Mass Destruction is the only way that gives some chance to survive...
 * And then she eventually crosses the Despair Event Horizon in Hand of Fire and commits suicide. Convinced that she accidentally fried her true love, Narm Tamaraith, with a spellfire blast. (Hint: She didn't, and Alustriel had to lie her silver-haired hiney off to keep Narm from jumping off a cliff right after her when he finally woke up.) Great way to end the story, Ed. Really.