Do classes in KOTOR 2 stack?
Every (few) levels depending on your class you can choose a certain amount of skills/force powers.
For example: A https://strategywiki.org/wiki/Star_Wars_Knights_of_the_Old_Republic_II:_The_Sith_Lords/Classes gets 2 force powers every 3 levels (and 1 every other level)
But a prestige class like a https://strategywiki.org/wiki/Star_Wars_Knights_of_the_Old_Republic_II:_The_Sith_Lords/Prestige_classes gets only 1 every level.
So if I choose to become a Jedi Weapon Master do i lose the extra force power every 3 levels or does it mix? (that i get the best of both worlds or do i fully become a weapon master?)
Each level you gain is in a particular class. Each level of each class grants the same things whenever you take it.
E.g. you are a Consular 17 and level up. You could pick Consular for your next level, and get the benefits of Consular 18, or Weapon Master, and get the benefits of Weapon Master 1.