Sword of Spirit
Legend
I consider my world to be one for people who love classic (pre-3e) D&D fluff. In feel it is somewhere between Greyhawk and the Forgotten Realms. It's own twists are intended to add unique identity without pulling the game farther from the default world assumptions.
Here's how it works out:
Races
New races like Dragonborn or Goliath don't exist in the world. Exotic races like Tiefling (with Planescape fluff), Genasi, or Aarakocra, are exotic, very rare, and people are probably afraid of them or don't know what to make of them. Savage races like Orcs are present and generally feared and not part of civilized society. Same goes for something like Drow. People consider them nasty evil creatures (since most are), and fear them, as they did in classic D&D. By far, the most common races are human, dwarf, elf, halfling, gnome, and half-elf--in roughly that order. Human lands are 95%+ human, and other races are even more dominant in their own realms. This creates a world where the wondrous and exotic can feel more wondrous and exotic, because it has a less exotic baseline to compare to.
Classes
I allow all the classes (and probably subclasses) currently in 5e. Classes are generally actual things in the world--not just rules abstractions. Subclasses are situated in the world. For instance, the Oath of Vengeance Paladins are a group of secret assassins for a church of order and civilization. They operate under the supervision of the clerics of that church, and target evil cults and the like (no, they don't murder heretics). So if someone wants to play an Oath of Vengeance Paladin, that is the fluff that comes with it. There may exist other Oath of Vengeance Paladins in far-flung reaches of the world that have yet to be detailed, but they will similarly have a place in the world. The different Druid subclasses represent different things based on location. In one part of the world Circle of the Land druids are the local default priests. In another, they are basically just "nature mages" and not primarily religious (though they recognize that the power of nature is metaphysically divine rather than arcane). Circle of the Moon druids are mostly loners out in the woods being savage, and the other Circles from Xanathar's are similarly unconnected to any real hierarchy or religion. Some subclasses are less specific, though still situated in the world. For example, a Samurai warrior is a Fighter. Most of them will have the Samurai subclass, but some might have the Battle Master, or perhaps even the Kensei Monk subclass. None of them are Paladins, Rangers, or Barbarians though. Fluff isn't disposable. For instance, you can't be a Monk without recognizing Ki as an actual mystical resource you are drawing on. The class isn't just a way to be an unarmed warrior that you can reflavor to taste. Ki is not part of every culture (only Far Eastern themed ones). (Also, "Monk" is a misnomer, since members of that class are martial artists not religious devotees. The class is renamed Budouka. While some of them do live in cloistered schools on mountaintops, others might have schools in more civilized areas. Actual "monks" are clerics.) All classes are not part of all cultural regions. I take inspiration from the old Oriental Adventures and Arabian Adventures material to determine which classes or subclasses (as well as races) are appropriate in the sorts of areas governed by those product lines, for instance. Races also vary by region. You could be a Spirit Folk or Hengeyokai Monk, but asking to be a Wood Elf Monk is an abomination against all that is good and decent. Also
I think anyone who has not played classic D&D as I'm describing it above is missing out. There are other flavors of play, but this is a flavor everyone should have the opportunity to get a good taste of at some point in their D&D experience, since it helps you better understand the game's history. If you've only played in worlds with Star Wars Cantina taverns, or even fun worlds that change all the expectations (like Dark Sun or Eberron), your experience is incomplete.
World Scope
A flat disc-shaped world that is about 60,000 miles in diameter. That's one of the twists I mentioned. I favor a top-down then bottom-up approach to design. Here's how it works:
1) First decide on what your world is all about. Answer the sorts of questions the OP asked. Determine if their are any important themes that need focused on, etc.
2) Come up with a brief historical overview of the ages of the world. Mine would be something like:
First Age - Exotic, epic fantasy. Think Dark Crystal, or even worlds visited during the Clone Wars. Gods walk the land. A Steampunk/Magictech society near the end. Ended with a physically world-shattering cataclysm that left few remnants and nothing but myths. Unknown duration; basically began as the world was being created.
Second Age - Origin of the races as know them from primitive beginnings. Dragons, Giants, and powerful unique creatures rule, then lesser races are gradually introduced, and by the end have freed themselves from the dominion of those powerful species and established great kingdoms. Lesser physically world-shattering event ends it, and society collaspses. Lasts tends of thousands of years.
Third Age - Inspired by the Hyborian Age. Races gradually rebuild societies.. Most varieties of ancient sword and sorcery themes are at home here. Atlantis sorts of realms too. Ends with a serious of wars that (figuratively) rip the world apart. Lasts many thousands of years.
Fourth Age - Begins with the founding of a great human empire that ends the chaos of the previous age. Thematically similar to a time frame running from Sumeria to the establishment of another great empire at the end similar to the Roman Empire. Many empires and kingdoms come and go, and the modern cultures start to become established. Ends with the collapse of the great Roman Empire analogue. Lasts several thousand years.
Fifth Age - The "current" age. Standard medieval D&D assumptions, with many kingdoms and lands. Civilized human scholars are familiar with major events of the Fourth Age (particularly the latter part), but everything before that is legend, myth, and scraps. Elves and similarly long-lived races have a recorded history that goes back further.
I also split those ages up into "Times" which I gave certain overall themes to. This stuff is a skeleton, not something to detail with precision.
3) Decide what the major parts of your world map look like. For instance, maybe the western side of Continent A is traditional European themed fantasy, the northern side of Continent B is Asian themed, Continent C is a throw-back to the Third Age, etc. You might want to define which human ethnic groups and cultures are most prevalent in which regions--this can hint at past migrations. This, again, only needs to be skeletal.
4) Leave plenty of room undefined. You might write in "Vikings" in a certain area, and "Middle-East" in another. But leaving blanks means that if you realize you wish you had created more Vikings with a different twist somewhere else, you can later add them! If all the areas border directly on another defined area, you don't have space left to add things you didn't think of originally.
5) Zoom in and provide however much detail you need for particular areas (such as a campaign starting area) as needed.
The value of doing it this way (skeletal outline including geography and historical overview, followed by targeted area bottom up) is that you won't accidentally end up with something like the Forgotten Realms--which was thematically supposed to be primarily European-themed, but by geography ended up with more land space devoted to just about everything else because they kept setting exotic things on the edge of the known world, then as the world got bigger the original area became a small region surrounded by an exotic world. That Forgotten Realms result is a pet-peeve of mine. Drawing a rough world map lets you decide things like, "I want approximately 40% of this world to be East Asian inspired" and then reserve that 40% so you don't accidentally end up covering half of it with Viking-land. If you really don't care how your world ends up looking, feel free to start with nothing but a town and build everything around it bottom up. But again, using this top-down skeleton is something I recommend to anyone who does care about how the world will end up looking and hasn't tried this sort of method before. If you aren't terribly particular, you can do this in a few hours.
Gods
People refer to them mostly as Immortals, Powers, or Immortal Powers, with nods to BECMI and Planescape. They are still called gods, but generally in context of particularly devout worshipers, rather than as a "creature type." Gods refer to anything worshiped, rather than a particular metaphysical order of beings. They follow general D&D conventions. Here is where I put another interesting twist that doesn't make it feel distant from default fluff assumptions: I have a human pantheon that is essentially composed of 2 1/2 related pantheons. One of them supports a single organized church feel, while the other supports a more loose pantheon feel, and the 1/2 is a set of primal Powers that are honored by both. Subclasses are very situated in the world. Clerics of most Immortals have a single Domain available to them. Some of them have two. Each Domain within a religion represents a separate order of priesthood or something similar. I do not follow the PHB assumptions that Clerics of any non-evil deity can select the Life Domain. Domains are matched up with Immortals in such a way as to enable the classic feel of D&D clerics, while also allowing for a wide variety of other options. 5e's approach towards the interaction between mortals and deities is pretty close to mine. They mostly interact by means of communication with their Clerics, which might even be limited to spells like commune, for some most distant Immortals. Their followers don't necessarily interpret everything about them correctly. For instance, some followers might believe that some Immortals are opposed to or at war with others, while those Immortals might actually get along swimmingly, which might be what some other follows believe.
A random fun thing I'm considering is to have there be a "Bardic College" as an actual organization that spans a large cultural area and wields political power, etc (like the medieval Catholic Church).
The overall scope of the history and geography of the world allows me to create a location for just about any adventure or campaign idea I might want to run, and the specific details of religion and culture give grounded connections and inspiration for individual characters. Rarely would I have to create a new world for a particular adventure idea, because I can probably find somewhere in the landscape and history of this world to fit it. (And if not, I also follow the AD&D/5e multiverse idea, with all the other classic settings being in the multiverse, and the potential of Spelljamming to connect them).
Here's how it works out:
Races
New races like Dragonborn or Goliath don't exist in the world. Exotic races like Tiefling (with Planescape fluff), Genasi, or Aarakocra, are exotic, very rare, and people are probably afraid of them or don't know what to make of them. Savage races like Orcs are present and generally feared and not part of civilized society. Same goes for something like Drow. People consider them nasty evil creatures (since most are), and fear them, as they did in classic D&D. By far, the most common races are human, dwarf, elf, halfling, gnome, and half-elf--in roughly that order. Human lands are 95%+ human, and other races are even more dominant in their own realms. This creates a world where the wondrous and exotic can feel more wondrous and exotic, because it has a less exotic baseline to compare to.
Classes
I allow all the classes (and probably subclasses) currently in 5e. Classes are generally actual things in the world--not just rules abstractions. Subclasses are situated in the world. For instance, the Oath of Vengeance Paladins are a group of secret assassins for a church of order and civilization. They operate under the supervision of the clerics of that church, and target evil cults and the like (no, they don't murder heretics). So if someone wants to play an Oath of Vengeance Paladin, that is the fluff that comes with it. There may exist other Oath of Vengeance Paladins in far-flung reaches of the world that have yet to be detailed, but they will similarly have a place in the world. The different Druid subclasses represent different things based on location. In one part of the world Circle of the Land druids are the local default priests. In another, they are basically just "nature mages" and not primarily religious (though they recognize that the power of nature is metaphysically divine rather than arcane). Circle of the Moon druids are mostly loners out in the woods being savage, and the other Circles from Xanathar's are similarly unconnected to any real hierarchy or religion. Some subclasses are less specific, though still situated in the world. For example, a Samurai warrior is a Fighter. Most of them will have the Samurai subclass, but some might have the Battle Master, or perhaps even the Kensei Monk subclass. None of them are Paladins, Rangers, or Barbarians though. Fluff isn't disposable. For instance, you can't be a Monk without recognizing Ki as an actual mystical resource you are drawing on. The class isn't just a way to be an unarmed warrior that you can reflavor to taste. Ki is not part of every culture (only Far Eastern themed ones). (Also, "Monk" is a misnomer, since members of that class are martial artists not religious devotees. The class is renamed Budouka. While some of them do live in cloistered schools on mountaintops, others might have schools in more civilized areas. Actual "monks" are clerics.) All classes are not part of all cultural regions. I take inspiration from the old Oriental Adventures and Arabian Adventures material to determine which classes or subclasses (as well as races) are appropriate in the sorts of areas governed by those product lines, for instance. Races also vary by region. You could be a Spirit Folk or Hengeyokai Monk, but asking to be a Wood Elf Monk is an abomination against all that is good and decent. Also
I think anyone who has not played classic D&D as I'm describing it above is missing out. There are other flavors of play, but this is a flavor everyone should have the opportunity to get a good taste of at some point in their D&D experience, since it helps you better understand the game's history. If you've only played in worlds with Star Wars Cantina taverns, or even fun worlds that change all the expectations (like Dark Sun or Eberron), your experience is incomplete.
World Scope
A flat disc-shaped world that is about 60,000 miles in diameter. That's one of the twists I mentioned. I favor a top-down then bottom-up approach to design. Here's how it works:
1) First decide on what your world is all about. Answer the sorts of questions the OP asked. Determine if their are any important themes that need focused on, etc.
2) Come up with a brief historical overview of the ages of the world. Mine would be something like:
First Age - Exotic, epic fantasy. Think Dark Crystal, or even worlds visited during the Clone Wars. Gods walk the land. A Steampunk/Magictech society near the end. Ended with a physically world-shattering cataclysm that left few remnants and nothing but myths. Unknown duration; basically began as the world was being created.
Second Age - Origin of the races as know them from primitive beginnings. Dragons, Giants, and powerful unique creatures rule, then lesser races are gradually introduced, and by the end have freed themselves from the dominion of those powerful species and established great kingdoms. Lesser physically world-shattering event ends it, and society collaspses. Lasts tends of thousands of years.
Third Age - Inspired by the Hyborian Age. Races gradually rebuild societies.. Most varieties of ancient sword and sorcery themes are at home here. Atlantis sorts of realms too. Ends with a serious of wars that (figuratively) rip the world apart. Lasts many thousands of years.
Fourth Age - Begins with the founding of a great human empire that ends the chaos of the previous age. Thematically similar to a time frame running from Sumeria to the establishment of another great empire at the end similar to the Roman Empire. Many empires and kingdoms come and go, and the modern cultures start to become established. Ends with the collapse of the great Roman Empire analogue. Lasts several thousand years.
Fifth Age - The "current" age. Standard medieval D&D assumptions, with many kingdoms and lands. Civilized human scholars are familiar with major events of the Fourth Age (particularly the latter part), but everything before that is legend, myth, and scraps. Elves and similarly long-lived races have a recorded history that goes back further.
I also split those ages up into "Times" which I gave certain overall themes to. This stuff is a skeleton, not something to detail with precision.
3) Decide what the major parts of your world map look like. For instance, maybe the western side of Continent A is traditional European themed fantasy, the northern side of Continent B is Asian themed, Continent C is a throw-back to the Third Age, etc. You might want to define which human ethnic groups and cultures are most prevalent in which regions--this can hint at past migrations. This, again, only needs to be skeletal.
4) Leave plenty of room undefined. You might write in "Vikings" in a certain area, and "Middle-East" in another. But leaving blanks means that if you realize you wish you had created more Vikings with a different twist somewhere else, you can later add them! If all the areas border directly on another defined area, you don't have space left to add things you didn't think of originally.
5) Zoom in and provide however much detail you need for particular areas (such as a campaign starting area) as needed.
The value of doing it this way (skeletal outline including geography and historical overview, followed by targeted area bottom up) is that you won't accidentally end up with something like the Forgotten Realms--which was thematically supposed to be primarily European-themed, but by geography ended up with more land space devoted to just about everything else because they kept setting exotic things on the edge of the known world, then as the world got bigger the original area became a small region surrounded by an exotic world. That Forgotten Realms result is a pet-peeve of mine. Drawing a rough world map lets you decide things like, "I want approximately 40% of this world to be East Asian inspired" and then reserve that 40% so you don't accidentally end up covering half of it with Viking-land. If you really don't care how your world ends up looking, feel free to start with nothing but a town and build everything around it bottom up. But again, using this top-down skeleton is something I recommend to anyone who does care about how the world will end up looking and hasn't tried this sort of method before. If you aren't terribly particular, you can do this in a few hours.
Gods
People refer to them mostly as Immortals, Powers, or Immortal Powers, with nods to BECMI and Planescape. They are still called gods, but generally in context of particularly devout worshipers, rather than as a "creature type." Gods refer to anything worshiped, rather than a particular metaphysical order of beings. They follow general D&D conventions. Here is where I put another interesting twist that doesn't make it feel distant from default fluff assumptions: I have a human pantheon that is essentially composed of 2 1/2 related pantheons. One of them supports a single organized church feel, while the other supports a more loose pantheon feel, and the 1/2 is a set of primal Powers that are honored by both. Subclasses are very situated in the world. Clerics of most Immortals have a single Domain available to them. Some of them have two. Each Domain within a religion represents a separate order of priesthood or something similar. I do not follow the PHB assumptions that Clerics of any non-evil deity can select the Life Domain. Domains are matched up with Immortals in such a way as to enable the classic feel of D&D clerics, while also allowing for a wide variety of other options. 5e's approach towards the interaction between mortals and deities is pretty close to mine. They mostly interact by means of communication with their Clerics, which might even be limited to spells like commune, for some most distant Immortals. Their followers don't necessarily interpret everything about them correctly. For instance, some followers might believe that some Immortals are opposed to or at war with others, while those Immortals might actually get along swimmingly, which might be what some other follows believe.
A random fun thing I'm considering is to have there be a "Bardic College" as an actual organization that spans a large cultural area and wields political power, etc (like the medieval Catholic Church).
The overall scope of the history and geography of the world allows me to create a location for just about any adventure or campaign idea I might want to run, and the specific details of religion and culture give grounded connections and inspiration for individual characters. Rarely would I have to create a new world for a particular adventure idea, because I can probably find somewhere in the landscape and history of this world to fit it. (And if not, I also follow the AD&D/5e multiverse idea, with all the other classic settings being in the multiverse, and the potential of Spelljamming to connect them).
