I was in a game where this type of thing got screwy. The GM played a VERY loose system of 3.5 (meaning he basically winged everything and numbers weren't really that important). Anyways, he believed that players should BE their characters and be in-character all the time. Well, one of the players had a different opinion. She said, "I don't lie well, but
my character does. Why should I have to actually think of how my character would bluff? Do you want me to actually try and swing my quarterstaff? And do you REALLY want me to sit here and actually try to pull off a Light spell?". Dave (the GM) really had no response and the game died the next session anyway. But Lindsay brought up a valid point. We aren't our characters. We shouldn't be required to convince the king to set us free anymore than we should actually have to pick a lock so that our rogue succeeds. The mechanics are there to give players an accurate gauge on how
their characters would handle a given situation. In my games, we are playing around with a complex skill check variant I found here at EnWorld. So far, the players love it. It's a game mechanic that makes success or failure dependent on the character, not the player. Players are still roleplaying, but reacting within the parameters of the results of multiple rolls so they can visualize what is happening. It's not really fair to let highly charismatic players talk their characters out of every situation while the shy one in the group just has to sit back and follow along and watch their characters suffer because they don't possess the same skills as the players running them.
I actually don't even really get the whole "dump stat" idea anyways. In a balanced adventure, characters should be faced with situations that require all of their ability scores at some point. If a fighter wants to use CHA as his "dump stat", fine. But his gruffness and lack of social etiquette should have some consequences if the GM is trying to challenge the party. Granted, if a fighter is playing in a "kick in the doors" campaign, then his CHA will almost never come into play. My players treat all of their stats as important on some level. A low stat does represent a character weakness, but the player should be aware of that and roleplay his character accordingly. They could also think of ways to compensate for that low score. For me, it's the range of ability scores that make characters unique. One less stat would seem to make them less unique. I guess that some DM's only throw things at their characters' strengths, but my players don't like that kind of game (that's how I used to DM). The real challenges for my players is when the crude barbarian has to talk his way out of being hauled off to jail, or when the clumsy cleric is the only one that can cross the beam over the lava flow to flip the switch and release his friends (sorry for the cheesy examples
).
As I was typing this, I realized that the "dump stat" idea must have been born out of the point buy system. We don't use point buy. I've got one player in my group who has been playing since 1980 and another since '78ish. They prefer the "luck of the roll". They actually let the dice somewhat determine what character they are going to take (we roll 4d6 and throw out lowest, 6 times, in stat order, pick the set you want). The more I think about it, I can kind of see where someone using point buy might want to do something like this. It has just seemed to me that the point buy is another symptom of reducing characters to statistics, and just focusing on the numbers, rather than the soul, of the character. I know that it's a more statistically balanced way to generate character parties than rolling, and I know that some players actually have a very specific character they want to play and the point buy system allows them to build it.
And in regards to the assertion that charismatic players almost always play charismatic characters and shy players almost play shy characters, I have 2 examples of the opposite in my group. Aaron is a really quiet guy by nature. In fact some of my friends get a little nervous around because he is almost too quiet. But in our game, he plays a brash barbarian who is always reminding the other characters how he is always saving their bacon. On the other end of the scope is Scott. Scott is one of the brightest people I've ever met. He runs his own successful computer consulting company and he and I are usually jostling for position as the center of attention at our social gettogethers. But he is currently playing a Rogue with a lot of skeletons in his closet, so his character is pretty tight-lipped.
Rather than dump the dump stat, why not make it play more of a factor in your game so that people won't make it sooo low? If players know they are in a world where every stat will come into play at some point, they might not be so quick to throw a 6 into something to get that precious 18. Anyhoo, I'm not against your idea at all. I'm just offering an alternative to making characters less unique by eliminating a stat. I guess the only thing I disagree with is that players should be determining the success or failure of their characters instead of the characters. To me, the numbers are like an actor's script. An actor is still playing the part, but the script tells him how
his characters is reacting to the given situation. If a player rolls a 6 on his Diplomacy Check, then he would roleplay his character making a social faux pas, like belching or unintentionally insulting the king by speaking negatively of the Guard Captain, who just happens to be the King's nephew. I guess we use the skill checks to aid in our roleplay, not replace them. My group just uses the numbers to determine how their character would react or perform or what their character would say, not try and use their own personality to speak for the character.
At the end of the day, if all of your players want to drop CHA and think it will make the game better, I wouldn't hesitate to do it. But I would definitely run it by the players before instituting the rule. Some of them might not want to lose an ability score and have to speak for their characters. If they all do, it might just make for some really great roleplaying!
