Unlike most other role-playing games, Planescape: Torment is more about talking to people and remembering things than it is about combat. So it's best to tailor your character around those goals.
Of the six attributes, Wisdom is the most important. It increases the amount of xp you earn, it gives you more dialogue options, and it gives you more opportunities to recall things from your past. Intelligence and Charisma also help with dialogue, but not to the same extent as Wisdom.
Your character starts out with a score of 9 in each attribute, and you receive 21 points to increase these scores. We recommend taking Wisdom to 18 (+9) and Intelligence to 15 (+6), and then increasing the other attributes as you see fit. Each time you gain a level (for the first time) you receive another attribute point, and events during the campaign can give you attribute bonuses as well. So even if you ignore an attribute during character creation, you can increase it later if you want.
Constitution is retroactive, so whenever you add to it, you gain health as if you had had that Constitution score for the entire game.
There are four classes in Planescape: Torment, but your character can only be three of them: Fighter, Mage, or Thief. Your character starts as a Fighter, but trainers in the game allow you to change your class, so you can switch between the three options at will.
Planescape: Torment uses a different sort of class mechanic than the other Infinity Engine games. It's not really multi-classing. You only play as one class at a time, and you only earn xp for your active class.
You only receive a full hp bonus and an attribute point the first time you gain a level. If you subsequently gain that level with a different class, then you only receive +1 hp and no attribute point. For example, if the first time you reach level 6 it's as a Fighter, then you receive 10 hp, but if it's as a mage then you only receive 4 hp. Your hp total stays with you regardless of which class you are. Your weapon proficiencies and attacks per round also stay with you, making extra Fighter levels worthwhile.
At levels 7 and 12 you receive specialization bonuses, which are listed below:
- +1 Strength, Unlocks Proficiency 4 for a Weapon
- +2 Strength, +1 Constitution, Unlocks Proficiency 5 for a Weapon
- +1 Intelligence
- +2 Intelligence, +1 Wisdom, +5 Lore
- +1 Dexterity
- +2 Dexterity, +1 Luck
You earn the bonuses listed above based on the class you are when you first reach levels 7 and 12. If you're the same class both times, then the second bonus for the class replaces the first one. If you're a different class, then you only earn the first bonus for the two classes. Since you can earn a bunch of attributes while playing the campaign, we're partial to the Fighter bonuses since they offer something more. But you can also just switch to your preferred class as soon as possible and not deal with multi-classing at all.