Forgotten Realms

Forgotten Realms is an official Dungeons and Dragons campaign setting created by Ed Greenwood circa 1967 for his little stories, but was not part of the official Wizards of the Coast lineup until 1987 and has since been supported by WotC through all five editions of the game. The setting is supported by hundreds of novels' worth of lore by dozens of authors. It is also completely and utterly fucking overused, there is not one square inch of Faerûn that has not had a dead forest's worth of material written about it.

Setting

Set on the planet Abeir-Toril, most of the Forgotten Realms source material focuses on the continent Faerûn. Faerûn is pretty similar to pre-industrial Europe, with the exceptions of all of that crazy fantasy stuff. There is a plethora of nations, kingdoms, organizations, deities, and fully fleshed out NPCs who are ripe with political intrigue and conflict. There is absolutely nothing on Toril that has not been fully fleshed out, so there is very, very little room for your own stuff. All this shit however, was fucked up by 4e's Faerun, which is widely regarded as a disaster and a blatant attempt to force 4e's core cosmology onto Faerun for the crime of being too much like 3.5e's core setting; Greyhawk.

The setting's planet is commonly referred to as Toril, because that is the name of the planet that the setting resides on. In 4e, it was revealed that the reason it's full name was Abeir-Toril was because it had a twin from whom it was separated at birth, called Abeir, which was the home of the new 4e races. In actuality, it was named Abeir-Toril so that it would be the first entry in the setting encyclopedia.

Faerûn

Medieval/Renaissance Europe/Near East/Africa. The setting of the vast majority of D&D stories, including those of a certain dark elf, to top it all off with the center of attention in D&D videogames to boot. This setting provided inspiration for most of the 3e splatbooks.

Abeir

Home to the Dragonborn and primordial elementals, as well as all the new sub-giant races and whatever else was introduced in 4e. Ruled over by evil draconic overlords, barring a few kingdoms founded by rebellious giants and humans. Oh, and some weird undead empire that has magical undead-only portals connecting to all graveyards and mausoleums and crypts on Toril, which they claim as their territory.

Al-Qadim

Medieval Middle East/Hollywood Arabia. Neither mentioned in either 3e or 4e except as another set of stuff for casters, showing how stupid non-AD&D is.

Kara-Tur

Ancient China/Japan/India. Updated for 3e with the Book of Weeaboo Fightan Magic and Oriental Adventures, but never updated for 4e as a setting. Little bits of it was included in Dragon for 4e, covering Samurai and Ninja and horde themes as well as new monk stuff.

Maztica

Pre-Columbian South/Central America, the subject of the eponymous splatbook for AD&D. Was not updated for 3rd Edition, but skipped a generation and got an update for 4th Edition. In the form of being replaced by the continent of Abeir and having everything about it shunted into another universe. Wasn't in 3e either so fuck them.

Abridged History

Creation

Ao creates the twin sister deities Shar and Selûne. Shar is darkity darkness levels of evil and Selûne isn't. So naturally they hate each other. They swirl around in the void that is Realmspace for gods know how long until via catfighting, they accidentally create Toril and create a couple of gods, , mainly Chauntea and Mystryl. The latter going on to die several times and become Mystra Because she's a woman who couldn't fucking balance the byproduct of her creation, the Weave, which is the source of all magic, both Arcane and Divine. Things just got out of hand after that and next thing you know, you've got your campaign setting.

Karsus's Folly

In -339 DR an archwizard named Karsus attempts to save the Netheril Empire by making the only 12th level spell in existence- presumably. The spell robbbed Mystryl of her powers and magic for a short time and was really awesome, but then magic goes wild because a fucking epic-level caster does not equate to a level-uncapped deity that handles fucking magic everywhere. In short Karsus ruined everything for everybody on that day. Lucky Mystryl was there to sacrifice herself and put all of her powers into a young female wizard and rose again as Mystra. Marking the first in the goddess's long line of deaths and rebirths. This sparked all the shit that went down in the game Neverwinter Nights 2, and is the reason why Magic sort of meets a cap.

Times of Troubles

The Times of Troubles, also known as the Avatar Crisis, started in 1358 DR when the two deities Bane and Myrkul thought it would be a great idea to steal the Tablets of Fate from the overdeity Ao. As punishment Ao banishes all of the gods to walk on Toril as mortals(except for Helm who was to guard the gateway back into the heavens) until whoever stole them felt bad and returned them. During this time Mystra got some of her power back and thought it would be a brilliant idea to challenge Helm to get back into the heavens. Helm wouldn't have any of it and and bitch slapped her down the Celestial Stairway. She hit the bottom and died in an explosion of magic. Eventually some mortals, Midnight (who went on to be the next Mystra), Kelemvor, Cyric, and Adon of Sune, fixed everything and they got be gods for a reward. Except for Adon of Sune, he really got the short end of the stick on the loot table for that encounter. He lost faith in Mystra, committed suicide, then got his faith back and went on to frolic in the brothel in the sky. This even signaled the change from AD&D 1e to the second edition and magic changed in real time in correspondence to these events, depicted in the canon Forgotten Realms Comic book series, featuring Bruce Campell as an Ex-drug addict halfling, an ex-alcoholic Paladin, an Elf with expressions that would put the Laughing elf to shame, a hot golem, and other goodies.

The Spellplague

In 1385 DR the goddess Shar had the god Cyric stab the goddess of magic Mystra. This caused giant pillars of blue fire to ravage Toril, killing untold masses and driving most wizards to madness. One of the few wizards to be unaffected by the event is Szass Tam, who continues to be a badass. To make matters worse, unlike the previous times Mystra has died she couldn't reincarnate, a stunning development that "changes the rules of magic" which translates as another real-time spell-casting change for 4e rules. Instead of The Weave magic works on this lame Arcane Power Source. Oh and the setting jumps ahead 100 years and everything has gone to hell. And by hell, we mean the shameful pit of shitty retcons and shoving other cosmologies down the throats of established settings. Seriously, anyone can tell that the changes made to Faerun's settings were done so that it would be just like the core setting; I.E shitty and boring.

The Sundering

After four and a half years, it was finally realized that the Forgotten Realms had been fucked to the point that all of the fans now hated the setting. The setting was jumped ahead another 10 years and made the core setting of the game. It turns out being stabbed wasn't in fact enough to kill Mystra, she was just hungry and had wandered off to find a cheeseburger made of her own children. Abeir went back to where it belonged (non-existence) and several other dead gods who were deemed superfluous suddenly came back to life. Basically, The Spellplague was retconned.

This event was known as the 'Sundering' but the writers didn't want to piss off the fans, so they held off explaining what the fuck happened until the fans could tell them what, in their opinion, should have happened. While waiting to be told how to do their jobs, dragons attacked everyone, trying to rescue Tiamat from Hell where she had in fact NOT been since before the Spellplague but because she was there in every other setting, we're all supposed to pretend that she was, so mighty adventurers can stop her from escaping in a linear story which was easier than the likes of the first time this asspull was pulled with Bloodstone Pass, Fuck you Bahamut.

From there, various other intersecting adventure modules happened at roughly the same time, and since things were mostly back to the pre-4e days everyone was happy. Except dragonborn fans (and dragonborn, whatever you think of them, are still a damn core race), as the writers quickly killed almost all of them off, crammed them into a tiny reservation, and have yet to make a single dragonborn NPC for any adventure module yet released, just to rub salt in the wound.

Interesting Side Notes

• Drizzt will outlive all of his friends and he cries about this often until they fixed it.
• There was a time 420Drizzt was bearable, until all of his adventures amounted to the power of friendship and his magical power of secretly Lolth's blessing empowering him into a murderhobo edge lord that got so broken he BEAT FUCKING DEMOGORGON with the power of an anime power-up one shot asspull to SAVE THE UNDERDARK
• The Neverwinter Online scenario of this event had the Demon Prince smack him and his party straight into an Abyssal rift, after the generic shounen speech of the power of friendship which is a great way to retcon this entire event for a ranger beating a monster so hard to kill based on how much it can throw at a party in summon-spam alone, nevermind the threat the creature itself actually poses.
• Elminster has sex with Elvira who is polymorphed into a man. He also was turned into a woman once, he's effectively, a massive fucking degenerate that hasn't been killed off because plot Armour and horribly oppressive "good" organization of spies, scouts, and adventurers he tricks into doing his work for him, he also advertises Faerun as anything but a clusterfuck continent so full, it feels more like the description of the endless murderfest an MMORPG provides over an actual living setting.
• Szass Tam, A badass lich who is literally Ming the Merciless, operating an entire country in the same vein as the Belbin Work Model, ans structuring it based on magical school specialization,
• Larloch Feared Master of the Warlock's Crypt, and one of the few statted NPCs definitive of a finalized epic-level reached minmaxed PC wizard with so much shit in his arsenal he ranks as a DMPC in his own right, and together combined with Szass Tam, is literally the inspiration for the character Ainz Ooal Gown, or Momonga from the LN, Overlord.
• Tempus, the badass bro jock god of battle.
• The world goes to hell in the 4th edition.
• After apparently being killed by one of his only friends, the god Helm survived the Spellplague in the form of a goat.
• The first 3-D CRPG was set in FR.
• Jarlaxle the dashing drow mercenary had a three way with twin bronze dragon sisters named Tazmikella and Ilnezhra
• Khelben Blackstaff has a fear of Lawyers and will do ANYTHING in his powers to avoid them, even resorting to elaborate illusions of unwanted marital scenarios to avoid lawsuits from extraplanar entities (I am not making this up)
• The setting is so high magic that even before the current established era in 3.5 and onward, even back in Ancient Netheril, there were FUCKING LICHES EVERYWHERE.
• The God of Vampires does not give a fuck, do not try to make him, he will just try to eat you and fuck with you on his layer of the Abyss.
• His high priest fucks Lolth, and this is the reason why Drow like vampires so much
• The last time a vampire gave a shit in FR, he nearly conquered Baldur's Gate itself solo, but got his ass kicked because he went ahead of a forty-thousand undead strong army with a macguffin that literally made him Elder Evil, by technicality of demigod level strength which would have been even more broken anyway as he was a base vampire + vampire Lord
• Minsc was petrified, turned into stone, and kept preserved until marketing would call upon him again for a lackluster comic book series that is only good for shilling 5th edition products as bad as Neverwinter Online did and Siege of Dragonspear