Warriors in Knight need two basic stat points. Strenght and Health. Strenght will boost their attack, it is the main stat point that does to warriors. This also increases your weight limit to carry and Warrior Armors have certain Strenght Requirements and Health requirements. Health boosts your Health and your Mana, it also increases your defesne at a certain point in game(Knight Powerleveling).
Rogues' primary stat point is your guessed. Dexerity increases the attack power on rogues and it makes them miss less in their attacks. Rogues should also put stat points into Health, which increases their Mana and defense at some point.
Mages are very complex for me in game(knight online gold ), mages rely on builds mainly. But in my opinion, you should look into putting stat points into Magic Power increases their magic spell damages and into Intelligence boosts their mana.
