Huh. I think we may have extremely different views on player agency to determine their own character concept.
If that was in response to me, possibly. As DM, I build the setting and cosmology, therefore, I determine
- the available races
- the available cultures which includes such things are their subsistence patterns, political organization, the social stratification, Residence patterns, technology, religious beliefs and practices, methods of exchange/distribution, views on property ownership, views on crime and punishment, body adornment, naming customs)
- based on the above and other factors, I decide which official backgrounds, classes, class variants (e.g. the spell-less Ranger), and/or subclasses if any are available in each culture. I also includes certain third party material as additions or in place of official version material that may fit the campaign thematically, but does not work for me mechanically). This may change the starting equipment of a character.
- For clerics, I determine the deities, their domain(s), what the priesthoods are like (tenets, strictures, holy symbols, vestments, tailored spell lists)
[* ] For magic, I may remove or alter spells from the PHB and include some spells from the PHB and third party sources. bits of current events,
- and I determine the major NPCs, organizations (guilds, colleges, orders), etc as well as bits of history and current events for each culture. In some settings, this will include people (if any) that can teach magic to wizards.
Now, it is not my job to change things to include a player's favorite race, class, subclass, or spell, or any concept that they may come up with. It is the player's job to work within the above guidelines and others that I set (e.g. no evil characters, no-pre-planned multi-classing build unless another character can train you in a new class and is willing to do so). The characters may choose to have alternate beliefs about how society is organized, ownership of property, how laws are enforced, rules on marriage. That is fine, maybe they were exiled for their beliefs depending upon the culture or left on their own.
The characters can have goals (that work within the nature of the setting and cosmology) including: becoming the greatest hero of their culture, overthrowing a tyrant, starting a revolution (for good ends), becoming the leader of their tribe, clan, collecting food recipes from different cultures and then establishing an inn, finding a lost relative or love, killing some monster terrorizing the homeland (such creatures will noted in the culture notes), becoming the head of a thieve's guild, start a magic school or guild. You can even switch character goals as the campaign progresses. As long as it is possible within the setting and does not involve being evil, I will work the players. However, as a player you need to have your player convince the others to go with you which may require you helping them first.