engine:
LonePaladin:
Some races existed in the setting before, like aasimar, but the geographic changes of the Spellplague -- notably the 'return' of portions of Abeir -- made them more prevalent.
(I'm going to claim that wanting to understand settings falls under "advice.")
What's with the two parallel worlds? Was one of them the "standard" Realms, or did people play in both worlds? Was the "sundering" part of a change to the game, like a new edition, or something in the books or what?
Okay, history time.
In very ancient times, there was one world, called Abeir-Toril. Primitive, except for the elves, and the gods were fighting with the Primordials. Imagine elementals turned up to 11 then mixed with each other. Anyway, things got really bad and the chief god Ao split the world in two.
One part, called Abeir, got about a third of the landmass, all the primordials, and a smattering of other races (though, notably, no elves except for drow). And lots of dragons. So they had a lot of base-level elemental stuff, and lots of dragons. Did I mention a lot of dragons?
Anyway, the rest -- Toril -- got most of the land, all the elves, and all the gods. The two worlds coexisted, with Abeir being in a sort of pocket dimension that was physically in the same place as Toril, but otherwise cut off from it.
Now, the Realms has always been notable for having portals leading to other places. Some portals just bridge two spots on the map (like, say, one leading from a hilltop near Neverwinter to a similar hill in Cormyr). Others bridge elemental or astral planes (like the one in Myth Drannor that linked directly to one of the Nine Hells). Still others lead to completely alien worlds -- there was a persistent one that made a two-way link between Mulhorand and Earth's Egypt around 2000 BC. Seriously, they even had copies of the Egyptian gods.
Anyway, when the goddess of magic, Mystra, was assassinated by two other gods, this temporarily destabilized arcane magic in Toril. This had happened before, except this time one of the assassins had been secretly installing a double of the magic-stabilizing thing that drew from the Plane of Shadow, and
it went haywire too. This made a big explosion of wild magic that spread across the world, then went through the numerous portals into every plane of existence, and eventually reached Abeir.
When it did, it basically screwed up everything there too, to the point of grabbing entire landmasses and forcibly swapping them with sections of Toril. That's how dragonborn came into the Realms, and how genasi became much more common.
Whew!
engine:
LonePaladin:
My other choice would be a drow dark pact warlock, but that particular build (the Slow Poisoner) could be a bit of a hassle for a DM.
Hm, I don't know anything about it. A drow dark pact warlock seems like an okay choice, but if a character is particularly gimmicky in combat I do tend to feel like it distracts from the challenge and themes of the game.
Okay, I thought I'd described this before. The Slow Poisoner is a character concept I've had for a long time, that would be a total headache for a DM at a live table -- because its primary focus is ongoing damage. I'd worked out a way to make a Dark Pact warlock that could eventually tag people with mixed poison/necrotic ongoing, penalize their saves, hurt them for making their saves, and make the effects viral.
Not really a heroic character concept, as it implies a mindset that enjoys inflicting slow, lingering harm on people. Which, really, says "drow" to me.