Would it break any rules balance to give other races the same kind of ability score options that PH3 races get?I thought about it, and I don't see how this would affect the rules at all. If one were to start handing out additional +2 bonuses to third and fourth ability scores, sure, that would throw off the balance. Just rearranging the bonus, though? All I can see that "breaking" is the flavor of each race, which has nothing to do with the rules or game balance.
My second thought was that players might try to take advantage of this and create weird, illogical ability score combinations (like +2 CHA for Dwarves, when pre-4E Dwarves have historically taken a penalty to Charisma). I figured splitting the stats into Physical (STR, CON, DEX) and Non-Physical (INT, WIS, CHA) and only exchanging between them (like giving Elves +2 WIS and the option of +2 DEX or +2 STR because they're both Physical stats) would make sense. I compared the ability score options for the existing PH3 races, and they don't follow this pattern, so I guess we can scrap that idea.
I looked harder for a pattern in the PH3 races' optional ability scores, and I thought I found one. Some races offer a choice between DEX and INT (Githzerai, Changeling). Not consistent with my "Physical/Non-Physical" idea, but they do affect the Reflex defense and add to Armor Class. Other races offer a choice between WIS and CHA (Shardmind). So I figured, maybe they only offer ability score choices between those that key off the same defense? Then along stomps the Minotaur and Wilden with more inconsistent options: CON or WIS and CON or DEX!
Based on this, I guess there is no real pattern or precedent for which ability scores can be interchangeable.
So then I began to wonder: which ability score options would be available to the PH and PH2 races? Here's my opinion.