Character Aging and decrepitude are minutiae of the game that are totally unnecessary but all follow a certain path of decrepitude.
Typically decrepitude and age bring on a loss of strength, reactions, perception and reason. Intuition generally stays the same, as does charisma (in as much as the loss of reason can be countered by a winning charisma!) and vigor roughly stays the same (it is the last to go if it is high). Different species have differing impacts of decrepitude. Physical Beauty may be assessed differently with the onset of age as well.