This is a good questionIt's pretty widely agreed in theory that an RPG player's will should (perhaps with rare exceptions such as a mesmerizing spell) not be infringed upon in choosing a character's actions. However, it's a practical and an aesthetic question just where the line between character ability and player volition lies. For instance, what should be made of "mental abilities" such as intelligence, wisdom and charisma scores?
What are the practical implications of including the "mental abilities" of a character during play? Is it preferable aesthetically for a player to "play the stats" of the character? Or should the player's choices be driven by the practical circumstances of the game and the guided by the player's ability as much as, or more than, what's written on the character sheet?
For example, should a fighter with INT 5 be played as "dumb?" Or should the player play the character to the best of the player's ability with only minimal or no regard to the ability score?