Vince_Snetterton
Explorer
The original versions of D&D had aging tables, where chars lost or gained various stat scores. Now, they were not particularly useful as most chars either died or retired before reaching middle age. But the concept had merit.In 5e, stats measure capability, not capacity. (Otherwise, how could you improve them?) An 8 Int can simply mean you're a little less well-read than others, and as such aren't as aware of formal logic (puzzles, Investigation checks) and lack the theoretical grounding for wizardly magic.
The act of roleplaying doesn't have to be in "playing" your stats, it also comes in narrating the results of the mechanics in the context of your character.
What ability stats should be, are the opposite of what you state they measure (I don't think you are entirely wrong). Stats should be a measure of the current capability of a char, not its full potential. Chars are born with a potential, and that value is immutable. What they do to reach that potential in game, well, I guess it is abstracted in 5e, but badly. Suggesting that a 60 year old human is stronger than its 20 year old version is ridiculous. Same with Intelligence, Dex, and Con.
Now, Charisma and Wisdom, sure, I can see those increasing with age, to some degree.
A 30 year old human can be stronger than its 20 year old version, if the 30 year old started hitting the weights for the first time at age 28.
How should this concept be applied in 5e? I would say that aging tables SHOULD be applied again, but many of the abilities would move based on age, not ASI's. A 25 year old char that has been walking the planet, WILL be stronger than the 18 year old version that started out. That char will have innately picked up some life skills aka Wisdom, maybe even Charisma. Kids in the real world are by definition, idiots, and only get wiser with experience aka maturity.
Now, to apply changes to chars outside of ASI's, that fundamentally changes the game. Plus I can only begin to imagine the pushback when a DM says "Your char can't get any smarter after 4 or 5th level".