Very interesting reading so far. I have two approaches to this: first as a player, second as a DM. I'm currently DMing a campaign with restrictions, so I'll get to that in a moment.
Player Perspective
As a player coming to a table, either an established group or a new group, I tend to believe that I'm an invited guest that is being given an opportunity to explore the offering of the DM - be it a whole new campaign world, or a pre-established campaign setting. I understand the difficulty of creating an enjoyable night for a table and I don't want to do anything that could hurt that experience. As a matter of respect, I will ask what others plan on playing and what the DM would like to see in terms of flavor. Now, most of the time I can usually play my favorite: Warrior Type with a huge sword race unimportant - but I do like to make sure that no one else wants to take on that kind of role, and often go with my second favorite character type, holy warrior of X God who loves to heal his companions while shouting out his or her religion's scripture at the enemy. No matter what though, I ask lots of questions:
- Are warriors with big swords a common sight for people in the campaign world?
- Should I be a member of a recognized organization or are mercenaries common enough that I won't be out of place?
- What are the societal restrictions on weapons - how does the campaign world handle someone drawing a sword to slaughter an evil doer in the middle of a street (maybe not knowing that the evil doer is evil, like a human crime boss or some such)?
- What gods are there?
- What are the gods preferred weapons?
- What is worship like?
- Should my character be reserved or outgoing in their faith - i.e. would a cleric of this god seek converts or just be like "My God rocks suckers, you all ain't worthy enough to speak his/her name! And I'll smite you if you do!"
And so on and so forth. Sometimes the DM will respond "I have no idea, but if you can write up something quickly we'll run with it." Which is awesome. I can take some of the job off the DMs shoulder while not stepping on their toes.
DM Perspective
As a DM, my goal is to create an interesting and exciting night for my players. My goal, in any campaign setting, is to break conventions and create tension for the players. I will not be the DM that says "You see two orcs! Roll for initiative." Orcs are boring. Everyone knows them, and is fully familiar with them and what they do. Sure you can spice it up a bit - maybe one of the orcs is a sorcerer, but in general orcs are boring.
When my players sit down at the table I do make sure to tell them this. I tell them I do NOT, in general, run generic fantasy settings. I will often try to change things up and keep things interesting.
The most extreme I have ever gone was the creation of a 2E campaign world using the various Player's Options series. The race (class) choices were:
- Human (All)
- Human, Romany (As human, -M, but still allowed specialists)
- Gnome, Forest (F, R, C, D, T)
- Gnome, Rock (F, P, S, C, T)
- Gnome, Nightfall (F, S, C, T, B)
- Halfling, Stout (F, C, T, F/T, F/C)
- Halfling, Tallfellow (F, R, M, C, T, B)
- Halfling, Hairfoot (F, P, M, C, T, B)
Multi-classing was also allowed, but no one every did multi-class. The reason for this creation was that my group started inviting new players. Three people showed up one night, and despite asking that they hold off character creation until the day of, they all showed up with Drizzt clones. Every. Single. One. They were all deeply misunderstood Drow rangers. So we said there were no Drow in the campaign world, and there was much gnashing and wailing and the pulling of hair. They wanted an explanation, which was entirely due to my best friend (who I still keep in touch with despite it being many years):
The elves, a pompous and self righteous group were getting pretty pompous and much more self righteous then normal. The Dwarven clans, said "Enough is enough!" and packed up their mules and left their mountain fortresses to wipe every last elf off the face of the earth. The two races warred for centuries in unrelenting warfare which made WW1 look like a Sunday picnic. The end result? both species went extinct and created the "Grey Wastes" a land covered in the powdered bone fragments of millions of dwarven and elven dead.
And that was that. We've never forgiven Salvatore either. I'm not sure why my friend sacrificed the dwarves, but Rock Gnomes and Stout Halflings replace them fairly well. Nightfall gnomes were from the demi-plane of Shadow and moved to the prime material plane to escape a scourge of Shadow Dragons - the primary opponents in the campaign.
Current Campaign
In my current campaign setting, I banned Half-Orcs as I find orcs boring. That was all. I replaced them with Gnolls. You can play a gnoll using the half-orc stats, but with the cultural flavor of the gnolls themselves. I also replaced Dragonborn with Kenku (slightly modified, and renamed Corvidians), and am contemplating removing Tieflings, though I haven't found a replacement race I like enough yet. The world flavor is Eastern European and set in the late middle ages. Gnolls take on the role of the Ottoman Empire.
So far these restrictions have been met without any issue whatsoever, and all the players are loving the campaign setting and spent far more time in the city then I was anticipating. They wanted to explore the flavor of the world and I almost had to rail road them to get them to move out of the city!