That kinda makes me want to ask, in people's experience, how much influence should the GM have over player characters? Like, are magic pools that either add +2 Strength or reduce it by 2 acceptable (since the PC gets to choose to drink it or not)? Are magic items? Vetoing PC back story? Etc.
Magic pool: Interesting. I probably wouldn't gamble on it myself, but given that it's optional I could buy it. I would, however, expect that these effects be
explicitly stated to the player, or at least that the information given to the
character would enable an informed decision. (You will hear me use that phrase--"informed decision"--an
awful lot.) So, for example, "This is the Font of Kord, God of Strength! The worthy will receive his might, but the unworthy will be stricken. None can say who is worthy in advance; even Kord's own priests know their god does not like to be bound by rules. Of the people known to have drunk from the pool, about equal numbers have gained or lost strength." That would be a good, in-character way of presenting the information. It leaves the question open and a little scary, but gives the player (and importantly the character) equal odds of knowing what's going on. On the other hand, "This is the Font of Kord, God of Strength! Drink from it and you may be blessed or cursed--none can say until you drink!" would
not enable an informed decision, because you have no idea what the odds are. Perhaps it is like
the spring which became the river Dyne--almost everyone who drinks it loses, and only a few gain. Or perhaps it is the other way around! We have no idea.
"Magic Items" is far, far, far, far, FAR too broad for me to answer your question. What are you including in "magic items"? The alignment-changing things? The
gender-changing things? Cursed items generally? Without more information I can't say. A LOT of the craptastic cursed items from 1e and 2e would upset me greatly if foisted upon me without my knowledge, and most people wouldn't WANT them if they knew what they were, so they're pretty much right out. That said,
sentient items, or items that
provide temptations or rewards if the player accepts a change in the character (not just corruption--a Good sentient item could lead Evil people on a path to redemption, after all)...all of those things could be very fun. Because, again, you're able to make at least SOME kind of informed decision about what happens.
"Vetoing" is something I generally...even calling it "frown upon" is too strong a phrase. I
strongly prefer a DM who is willing to be flexible and adaptive, though that pointedly does NOT mean a DM who has to suborn all of his or her preferences to those of their group. This means DMs who are willing to give every request a fair hearing, and attempt to find a compromise that suits both parties. For example, let's say I come into a Greyhawk game wanting to play a Dragonborn. I would be irked if the DM just flat out said, "Nope sorry no Dragonborn in Greyhawk, try something else." I would be very pleased if the DM said, "Well, technically speaking there have never been Dragonborn in Greyhawk, but Greyhawk is just one part of a big world. Maybe you could be a wanderer from the deserts in the East (West? I don't know my Greyhawk geography well.), but that then leads to questions:
why are you wandering so far from home? Why do essentially no other members of your people come to Greyhawk, even to trade?" Through answering these kinds of questions and having a genuinely open, genuinely flexible dialogue leads to LOTS of fun and almost always increases my attachment to my character and the world the character exists in.
That said, there are certain circumstances where even straight-up "vetoing" is appropriate, but usually only when an explicit statement is made in advance (so that I, as a person choosing to play or not to play, can make an informed decision). For example, if the DM's pitch is, "You are a group of centaurs, going on a quest to (etc. etc.)..." then it seems pretty reasonable for the DM to say "No" if I want to play a Dragonborn. The campaign pitch has very specific races in mind. Similarly, a "humanocentric" or "Hyborian Age style" campaign carries particular significance; Dark Sun has specific connotations that make arcane casters risky to play, and divine casters non-existent. So I'm not trying to say that it is NEVER EVER okay for a DM to have hard rules; I just expect the DM to be specific about any and all hard rules BEFORE I have any chance to think about what I want to play.
To keep it on topic, I guess we should probably discuss this in terms of 4e. Like, how does 4e handle this classic play style preference issue? What does it encourage (wish lists come to mind)? I'm curious what people feel works best for their group, what works best for 4e, and how those things interacted.
Well, in general (although it's not an explicitly stated thing anywhere IIRC), 4e has a "say 'yes and' or 'yes but'" policy. All books and articles (unless they expressly say otherwise) are Core--and, in general, they did a very good job of maintaining a common standard of power. Further, it encourages DMs to have an open mind--not absolutely permissive, but always being willing to at least
consider what a player wants. As I've said elsewhere, "Anything which opposes player enthusiasm for a non-abusive idea should generally be avoided." This doesn't mean that EVERY SINGLE non-abusive idea is bad. Just that, in general, you want to
feed player enthusiasm, not fight it.
The "wish lists" are something, I guess, though I never really cared for them per se. Instead, I think DMs and players should just have a nice talk about the kinds of ways they want to play their character, and continue to have talks over time about what they're enjoying or not enjoying. So, for instance, a Rogue who wants to do an "Errol Flynn" kind of thing with rapier and cloak; DM takes that into account and that helps to shape what loot the party sees. Later on, the Rogue decides that that's not really doing it for her, so she's going to rebuild herself for being a cunning poisoner and dagger-fighter. This, too, shapes the kinds of things the group runs into.
There's also reskinning, which 4e explicitly encouraged on multiple occasions; there was even a Dragon article
specifically about the authors' advice to people who want to reskin stuff. It specifically said that, as long as it doesn't seem abusive or intended to make a strange combination, DMs should totally be willing to do stuff like changing the keywords and damage types of powers (I believe the specific example was changing a Wizard Fire power to Cold because the Wizard player wanted to be cold-themed).
Finally, 4e's Quests were a pretty big way for players and DMs to jointly shape the direction of both the individual character and the campaign as a whole. I haven't had much chance to see them in action, but I'm sure they would be helpful.