Your skill ranks, i.e. the points you put in them on level-up.

Be careful to distinguish between skill ranks and your skill value. Items, feats, and ability score bonus will not count towards skill ranks and help you qualify for prestige classes. In many cases, skill ranks are used as a way to enforce a minimum level restriction on prestige classes, so you're not meant to be able to bypass the restriction. Since your maximum possible skill rank in any one skill is based on your character level (3 + character level, to be precise), it's impossible to get around.

The prestige class requirements for base attack bonus, skill ranks, and spellcasting level cannot be circumvented. For many other requirements, however, there are ways to meet the requirements somewhat creatively. For instance, normally you'd need three levels of rogue to access arcane trickster, but it's also possible to qualify with one level of rogue and one level of shadow thief (two levels total).

Sorry, I have forgotten something

next question:

assuming you have the following situation:
- your character can make a sneak attac and has greater cleave
-There are several enemies close to each other
-The enemies attac something that is not you and they are not crit immun (= you can sneak attac them)

If you kill one of them with a sneak attac, do you do sneak attac damage bonus against the others as well, when greater cleave is automatically used?

Yes, stacking can be a little hard to follow in the NWN series. It's not consistent between NWN1 and NWN2, and it's not consistent with the actual pen and paper rules either. Definitely one of the nastier places.

Generally speaking in NWN1 stuff will stack unless you find something that says otherwise. In NWN2, stuff will not stack unless specifically stated otherwise. Ultimately you'll have to experiment to find out for sure. Because the series isn't even consistent with itself, I always have trouble remembering what does and doesn't stack. This is correct, you must succeed on an attack roll to "hit" the target or else the spell fails. No, a magic weapon should not grant a bonus on touch attacks (since the touch attack is itself considered a completely separate weapon). Keep in mind that most types of armor do not work against touch attacks, so it's generally a lot easier to hit targets with a touch attack than a regular attack. Many enemies have absolutely atrocious touch AC's, to the point at which you'll only ever miss on a roll of 1. No, it's not like a crossbow. A crossbow must pierce a target's normal AC, whereas a touch attack gets to ignore most types of armor, and will have a significantly better chance of hitting.

In Storm of Zehir, there are almost no alignment shifts. There were supposed to be none at all, from interviews, but I saw two. Instead, your alignment is one of the many things that determines which dialogue options are available for a character in your party to say.

Regarding stacking:
• Dodge armor bonus stacks with itself (up to a maximum of +20), but all other armor bonuses do not.
• Ability bonuses from equipment or spells do not stack (bonuses from feats are considered natural increases and do stack with spells/equipment). There is a cap of +12 on ability bonuses from a spell or equipment.
• Saving throws from spells and equipment do stack (up to a maximum of +20), with the exception that a bonus from two rings will not stack. Bonuses from feats do not count towards the +20 cap.
• Attack bonuses from all sources stack, but only up a maximum of +20 (however, there are some sources that don't count towards this cap, such as the weapon focus feats). BAB is consider separate from attack bonus and does not count towards the cap (similarly any spell or ability that increases BAB, such as Divine Power, does not count toward the attack bonus cap).
• Skill bonuses do stack, up to a maximum of +20.
• Damage reduction doesn't stack in most situations, although the DR from the Spirit Who Walks feat (lvl 20 Spirit Shaman) and the Warlock's class DR do stack.
• Spell resistance does not stack, although penalties to spell resistance do stack.
• Caster level only stacks between non-prestige classes if both classes give access to the same spell. Levels in certain prestige classes do stack with levels in the base class when determining caster level (Arcane Scholar of Candlekeep, Arcane Trickster, Eldritch Knight, Harper Agent, Pale Master, and Red Wizard of Thay for arcane casters, and Sacred Fist, Stormlord, and Harper Agent for divine casters).

Regarding touch attacks:
Touch attacks take into account different bonuses to attack and AC than normal attacks. Armor bonus, shield bonus, and natural armor bonus are not considered for touch attacks. Dodge bonus, deflection bonus, and dexterity modifier are counted. For attack, BAB is counted along with any general attack bonuses (this does not include enchantment bonuses on weapons, but does include bonuses from spells such as Bless or True Strike). For regular touch attacks the strength modifier is added to the attack roll, and for ranged touch attacks the dexterity modifier is added.

Regarding cleave and sneak attack:
Sneak attacks do work in conjunction with Cleave, provided each target you perform a cleave on satisfies the conditions for a sneak attack.

Thanks everyone.
Thats exactly what I wanted to know.

just two comments:
-If I ever make a warrior/thief combination, I call him "stealth bomber"

-(*crying like a baby)
This is not fair. I thought my barbarien/dwarven defender wearing heavy adamantite armor and shield,
encanted with damage reduction and having someone cast stoneskin on him is invulnerable.

Was this changed from NWN1? In NWN1, the maximum for skill boosts was +50. I thought it was the same for NWN2, but it's been a long time since I played it and could well be misremembering.

Yep, quite a few details were changed between NWN1 and NWN2 (such as ability bonuses stacking in NWN1), including dropping the cap on skill bonuses from equipment/spells from +50 to +20.

Cool, thanks for the clarification. I remembered the ability bonus stacking being changed, but had forgotten about the skill bonuses.

After lots of thinking I had some strange ideas.
Here are my newest questions:

-You can do sneak attacs with every weapon and even unarmed, right?

I had the insane idea (from a role playing point of view) to have a monk/paladin/rogue
Imagine the following situation:
A naked man jumps from behind a bush and says:
"Hello everybody.
I am Sir Lancelot of Camelot.
Nice to meet you.
Would you please give me all your money or else you will feel my fists of death."

After some more thinking I found a monk/assasin to be really powerful.

-You can harm undead with heal spells and heal them with inflict spells.
The highes damage I have seen in the oc of nwn2 was my cleric casting mass heal on a large group of undead.
The best thing is: she did this by herself. I did not give her any commands.

here comes the question:
In some final fantasy games (I will now refer to ff6) this is also the case.
And there are some other things. In ff6 you can:
- instantly kill any undead by using a revieve spell/item
-fully heal an undead by using an successful instant death ability
-I confused an undead and he used a drain life skill on his undead fellow.
This way, the caster killed himself by healing his friend with his remaining hp.

Does this also work in DnD and especially nwn1 and 2?

-A cleric with the evil domain can use turn undead on outsides.

Question 1: Outsiders are all creatures that are not from the same plane as the caster, right?
Does it mean it works not only against demons and devils, but also against elementals and gith?

Question 2. (this is a hypothetical one)
Asuming one of the gith you fight in the game is an evil cleric.
Could he use his turn undead ability against all "normal" people and animals?
The gith are not from the material plane after all.

Almost forgot something.

At the very beginning of MotB you get an npc whose familar can open locks and disarm traps.
Can a player character also have a friend with such skills?
In the oc I always had a rouge npc along. I really liked her.
But what if you don´t and you don´t want to be a rouge yourself?

Well, you can always just keep Safiya and her familiar in your party. There's also one Rogue NPC party member, but depending on your choices it may not be possible to recruit him.

Overall I wouldn't worry about it; there aren't a lot of traps in the MotB campaign

It should be possible, but last time I tried using "Raise Dead" on an undead, it just wouldn't let me target the undead with that spell.