D&D General Campaign Setting based on Venn Intersections of Other Settings

[Twiggly the Gnome]

I've been trying to brainstorm some salient themes for a setting based on overlapping tropes in published settings, so far I have:

Scions of Power - Eberron's Dragonmarks and Birthright's Blood abilities.

Monsterous Monarchs - Dark Sun's Sorcerer Kings and Birthright's Awnsheghlien.

A Magic Number - Eberron's Baker's Dozen and Planescape's Rule of Three.

Mutual Interest Clique - Planescape's Factions and Ravnica's Guilds.

Anyone have some more?

 

[Blue Orange]

Couldn't think of any crossover settings (the lore changes over the years have confused me too much), but what if you cross over roleplaying games:

Against the Elder Gods - D&D characters fight the Cthulhu Mythos. (This one made it into Call of Cthulhu d20.) You know, Call of Cthulhu's monsters don't have much in the way of magic resistance.

The Black Network of the Night- The Zhentarim are Embraced by Vampire's vampires, and all of a sudden the politicking in the Forgotten Realms takes an undeadly turn...

Blood for Gruumsh! Skulls for Nerull's Throne!- The orcs in the Forgotten Realms discover the Warp, and all of a sudden Chaotic Evil takes on a horrid new meaning...

Or even going beyond RPGs:

Swordsmen of Catan - robbers have plagued this land under development, it's time to stop them, but first you have to trade for wool, lumber, brick, grain, and ore to be able to make weapons.

Adventurer's Risk - so you've gotten to 20th level and want to take over the world. What, you didn't think every other high-level adventurer had the same idea?

 

[Rabulias]

Against the Elder Gods - D&D characters fight the Cthulhu Mythos. (This one made it into Call of Cthulhu d20.) You know, Call of Cthulhu's monsters don't have much in the way of magic resistance.

It's only fair. PCs do not have much in the way of insanity resistance.