A lot of this sort of thing can get nipped in the bud with sitting down with the players, before any character is created, and being extremely open about what your campaign is about and what you expect from it. Don't pussy foot around it and don't wait until you have problems to try to fix them.
Fear the Boot (a podcast I regularly listen to) calls it a Group Template. I think it's an absolutely fantastic idea. Instead of everyone going off to write up their characters, showing up on the first game day and trying to shoehorn things in, have a very detailed point form list of what your expectations are for the campaign and have everyone sit down and talk together about them.
Once you do this, and get everyone on the same wavelength, so many of these issues go away.
The above is pretty much what I do. However, at the character generation meeting, I come with a setting that includes the available PC races, the cultures and deities fleshed out. I also have a list of available classes and UA style class variants which are assigned to various cultures
For example, the upcoming campaign includes the following classes: Barbarian, Bard, Cleric (all are customized to the settings deities), Fighter, Knight (Hong's OA Samurai variant), Paladin, Psychic (Green Ronn), Ranger (spellcasting and non-spellcasting), Rogue, Shaman (Green Ronin), Sorcerer, Warrior Mage (AEG's Myrmidon), Witch (Green Ronin), Wizard (tentative), Wizard Specialist (using the UA specialist wizard variant abilities. It also includes the OA shaman with a few changes to make it a divine class.
Class variants include: Barbarian Hunter, Battle Sorcerer, Urban Barbarian, Wilderness Rogue, Martial Rogue, and several fighter variants (based off of the PHB section in customizing a character).
Now, not every race/class combo is normally available. Some combinations are only found in certain cultures, but I am willing to consider an unusual background that fits within the setting guidelines (e.g., a half elf Shaman growing up on the island of Maridian would be rare, but acceptable as a Maridian Shaman. However, any other non-Maridian would not be. Humans don't have blood ties to the spirits and any other race would be sacraficed.
We discuss the setting and cultures. People ask questions. They come up with possible ideas and we meet one on one or in small groups based on the cultures of interest to discuss the ideas. In the meetings, I give a little more info (e.g, some recent history, noteable NPCs and organizations, and cultural attributes), to help give the players more info some of which they might use as hooks.
Then they draw up backgrounds and we discuss them to make necesssary tweaks or fine tune the character.
I wonder what Gregk's situation is. If you're still reading this Gregk, do you have a fairly stable group or are you gaming with strangers often?
I am just finally having a stable group again after three years. The last stable group had been together for ten years or so.
The three replacements were only temporary. I knew up front that they were leaving for college within a year. However, all three moved several hours away. One ran off to live with her s.o in San Francisco and the other two moved with their parents. Two of the three still come to visit and game several times a year (so I figure that I am doing something right).
The current regulars include the two long term players and the five new players (four of whom have been gaming with us in my M&M campaign for the past year).
Now, does the stability instabilit of the group have anything to do with my GMing style? No.
The reason that the setting limitations are used are:
1) I prefer non-kitchen sink settings where the limitations help defind the setting. The one player, who initially had a problem with the idea of not playing his favorite class actually ended up with his favorite character of all time. The other players also found it to be their favorite campaign.
2. I like the players to know their choice upfront. The books used and what is and is not available gives everyone the same options to choose from upfront while keeping things manageable for me.
3. I keep the mechanics that reflect my mechanical preference or view of which mechanics better simulate how things work in the setting. For example, Malhavoc's Book of Iron Might over WOTC's Tome of Battle and Green Ronin's Psychic's Handbook over WOTC's PsiHB or XPHB.
4. It stops players in mid-campaign from going "Wow, this new race, class or mechanic or other new shiny thing looks interesting". Ok, I kill or retire my character so I can try it out.
5. Sometimes it does come down to just a personal preference- no dragonborn, half dragons, templated characters or tieflings. Rare, but it happens.
My question to you is, what if the player is willing to change the flavour, so that it suits your campaign world ?
It depends. Pretty much the actual uses of nearly every supplemental WOTC class, PrC, race, and alternative mechanic (ToB, ToM, MoI) is not open for discussion. I am familiar with them and not interested in using them (or fighting though what I consider really bad fluff and/or application of an idea)
Plus, for some classes or PrCs, I already have alternative set up:
- Duskblade or any other Arcane Warrior class- AEG's Myrmidon.
- Knight- Hong's Knight variant of the OA Samurai
- Psi-HB and XPH- Green Ronin's Psychic's Handbook (except no Psylocke energy blade characters)
- Scout: use the Martial Rogue (UA) w/ the wilderness rogue variant. I'll even let you upgrade hit die for 2 skill points/ level
- Spirit Shaman- Green Ronin's Shaman class
(heck, using the tried and true "fell down a rabbit hole and is trying to get home" trope works), would you still veto dragonborn
Yes, I would.
1). I don't like the planar trope. I like self contained worlds- perhaps, with some version of heaven and hell and, depending upon the campaign, a spirit world, dream world, and/or shadow world. So, no planar travel between various worlds- unless you are a shaman going into the spirit world or the character dies.
2) If I make one exception, it just opens a can of worms when somebody else wants some concept that doesn't fit.
3) Dragonborn will never be part of a world I run. I have no interest in a world with little mini-me breath weapon Godzillas.
Now, if they want to run a lizardman, I'm perfectly fine. I do have a lizardman race- the starting class choices are Barbarian (PHB or UA hunter variant), Fighter (ex-hunter variant), Shaman, Wilderness Rogue, Sorcerer, and Witch.