I have played this game years ago and I had to set it to easy to get past a Boss and later I failed pathetically at another Boss. I think I was a Paladin al the time (good combat skills and he can also heal), but I had problems remaining a lawful good alignment AND having a good relationship with the evil or chaotic chars of my group.
Before I mess up again, I better ask someone who knows better.

I also played Baldurs Gate1+2 and planescape tornment and I understood the rules very good, but things have changed much since then.

These are my questions to the new character system:

-What happens when a char gets an alignment that does not fit to his class?
Assuming i am a paladin and I become evil.
Does something happen in the moment when the alignment changes?
At the next lv up, can I become e.g. a fighter and still use the spells I learned so far?

-A lot of things changed regarding multi classing.
Assuming I am a lv. 10 fighter and I become a lv. 1 wizard.
Can the lv. 1 wizard still use a giant sword with the same skill as before?
And if the classes are reversed, can the lv. 1 fighter use the spells of a lv. 10 wizard?

-How important are "social skills" in this game?
With social I mean everything regarding dialogues and interactions with friendly npc (e.g. merchants).
As extreme examples, Icewind dale is all about fighting and in Planescape Tornment good talking is much more important than good fighting.

-I read the manual and saw, that you can learn to hold a 2-hand-weapon in 1 hand.
Is it possible to fight with 2 2-hand-weapons at once and is this useful?

-Is it a good idea to give one follower (who is not in your combat group) all crafting skills so you can make items with the mats you found in the dungeons?

-A good group should consist of 2 fighters, 1 thief and 1 caster, right? (I dont mean classes but the role they do in combat)

-After reading the manual and thinking about the reasons I failed last time (I stayed with one class, I spread my skills too much) I thought about the following char for a beginner:
A human or dwarf (fighter->barbarien->frenzy berserker) who specializes on one kind of two handed weapon and puts all points in combat (offensive and defensive). But I dont know what to do when I become lawful somehow.
Is that a good idea for a beginner?

EDIT:
-When I have a new class, can I still spent points in skills of the old class without penalty?

He retains all abilities he already had in the class, but can no longer gain further levels. So your Paladin retains all Paladin abilities and spells earned up until this point. You will never actually lose abilities because of alignment change in NWN.

In NWN1:HOTU there's actually a NPC party member with levels in both Paladin and Blackguard. It's a totally legit combo in the NWN series. You never actually lose abilities by multi-classing in NWN. Your combat skills won't improve as quickly if you multi-class wizard, but they also will not get worse.

Fair warning, Fighter/Wizard is significantly less powerful in NWN series than it is in the BG series. Casters in general have trouble multi-classing effectively in NWN. If you have your heart set on multi-classing with a caster, be sure to check out the prestige classes. Absolutely, your spellcaster abilities will be just as good as they were before (though they will not get better). This particular combo works much better using the Eldritch Knight prestige class (you just need to sink a feat for martial weapon proficiency to qualify) rather than Fighter. Totally depends on what module/campaign you're playing and how you want to play it. It's entirely possible to go in guns-blazing and still complete all the quests, but that might not be the most satisfying way to clear the game. This isn't Planescape Torment, but it's not Diablo either. My first NWN2 OC campaign run was played with a pacifist bard who never touched a weapon, and I loved him. For MotB I respecced him as a Sorcerer since I found the NPC roster didn't have enough fighters to really leverage the huge number of buffs and debuffs I could spam.

In most campaigns (Storm of Zehir is the only official campaign that works otherwise) your NPC followers cannot use social skills, so don't bother with assigning such skills for them. For your main character, generally it's a good idea to pick one or two social skills and max those out.

The only notable exception to this is bluff. If you have the feint feat it can be used in combat. Yes, but you need to select the Monkey Fist feat to do this. Yes, it is possible to dual-wield two-handed weapons in this manner. No, this is not useful; you're stacking so many accuracy penalties that you'll never actually hit anything with this combo.

Generally speaking in NWN, using a two-handed weapon in one hand is a poor deal. The bonus for two-handing a weapon is so great that it often makes sense to use a one-handed weapon in two hands! The only case I find it useful to use monkey fist is if you you're completely specialized in a two-handed weapon, but want to occasionally use a shield. Otherwise, just use a one-handed weapon; you'll hit more often and you'll end up dealing more damage. If you want to take an accuracy penalty in order to deal extra damage, use the power attack feat. You can make one follower your "crafter specialist" or give different crafting skills to different followers. It's your choice of how to do it. It's entirely possible to play the game without crafting at all, if you're not interested in it. Keep in mind that the most powerful recipes can only be completed by wizards and clerics. The "craft wondrous item" and "craft magical arms and armor" are the big ones. There are lots of ways to build a group. A group like that will work just fine. Yeah, the original campaign has a lot of lawful shifts in its conversation paths. Complicating matters is that a lot of activities don't register as chaotic (ie, breaking and entering into a nobleman's estate), making it difficult to counter-balance them. The only reliable way I've found to stay chaotic is to consistently insult and lie to people whenever those conversation options pop up. Otherwise it's very difficult to avoid being lawful by the end of the campaign. There are some pretty big lawful shifts in there on conversation paths that amount to nothing more than being polite.

For a tanking melee character, I prefer Fighter into Weapon Master using a two-handed weapon. Dip for some Rogue levels if you want to add some skills to the mix. I recently finished a solo-playthrough of NWN1 OC using this combo (ended as Fighter 6 / Rogue 4 / Weapon Master 7). If you have a half-decent charisma, Divine Champion also is a nice way to be a pseudo-Paladin. No. However, the "Able Learner" feat removes the cost penalty. This is a great feat for wizards who have a lot of intelligence to grant them extra skill points but few class skills to assign them to.

Regarding social skills: Since as Darvin said, the Storm of Zehir campaign is the only one of the packaged campaigns that allow you to have other party members use their own social skills (unless Mysteries of Westgate allows it too. I haven't played that one yet), if you want to change it so that your main character doesn't have to be the social one, you can try this user-made mod, which adds SoZ conversation options to the original campaigns.

NWN2 OC Makeover SoZ Edition
http://nwvault.ign.com/View.php?view=NWN2ModulesEnglish.Detail&id=393

Thank you for your help.

Can you learn several prestige classes?
If yes, I make a dwarf and start as fighter.
As soon as possible I become a frenzy berserker (if unlawful) or a dwarven defender (if lawful).
Than I try to become a weapon master as soon as possible (you need lots of feats for this).
I start caotic neutral (lets see how long I can stay unlawful) and use only one 2-handed-sword.

If you can have only one prestige class I make
fighter->dwarven defender or
fighter->barbarien->weapon master (a human might be better in this case)

starting stats:
str 18 (tons of damage and hit, this will be increased further)
dex, con, int 14 (you need dex and int 13 for most advanced combat feats)
wis 8, cha 6 (I dont need to be wise or beautiful to kick some asses)

Yes, you can have up to 4 different classes. For example, you could a have 1 base class and 3 prestige classes or just 4 base classes. The combination is entirely up to you.

Thanks everyone

The mad berserker will start to destroy the world in 10, 9 . . . (long tinking) . . . whatever comes next, I am a mad berserker and not somebody who studied math . . . (wait a little longer) . . . NOW ! ! !

Not only that, but prestige classes are exempt from multiclassing penalties.

When I play the game or try something in the character creation, more questions rise up.

The game manual is more than enough to play the game but I dont understand the whole system behind it. Can you read this somewhere? This is DnD 3.5 and the games KOTOR (I played part 1) and Icewind dale 2 (not played yet) have the same system, right?

So these are some things I need to understand:

-If you give your char one level as fighter (or something similar) he can use any armor or weapon. This is a good idea for everyone except pure spellcasters.

-Rogues can use the sneak attac with any weapon and it is enough when they stand behind an enemy who attacs somebody else. But it is better when you use stealth mode and dual wield small weapons.

- When you trained to fight unarmed, do you attac with both hands? In some sense, you can regard boxing as dual wielding a glove. I try to imagine how stupid it looks, when a boxer attacs his opponent every 6 seconds with a right punch.

-Is there a global round or does it calculate the rounds for each battle participant seperately?

-A level adjustment of x for some races means that in order to reach level n, you need the exp for lv n+x.
I thought a drow cleric would be cool, but beeing always 2 levels lower than everyone else will be hard.
But in my first playthrough I use a melee master anyway.

-I dont really understand the concept of "attacs of opportunety".
It means, when I attac somebody who does something different than attacing me with a melee weapon, I will get an additional attac with a hit bonus against him once per round, right?
But the manual says also something about movement that I did not understand completely.

-The parry skill is only useful when you are in parry mode, right?


These are enough questions for now.
I really like the freedom of character creation you have in this game.
I you do it right, you get exactly the char you always wanted to have and become extremely powerful.
But you can also create something ultimatly useless, like a mage who cannot cast any spell because he has no intelligence.
And anything in between.

I can answer a few of these: IWD2 uses the 3.0 rules, which are very similar. I can't recall offhand what the rules in KotOR are based off. You can read the 3.5 rules System Reference Document Here, which is a lot of material, but you should be able to fairly easily pick and choose what to read to get a good grasp of the system. I wouldn't say it's a good idea for 'everyone', but it can certainly be useful for many classes. And I also wouldn't exclude spellcasters. It depends on what you have in mind for the character. What do you mean by it's 'better' to use stealth? It can be quite effective yes. But if you mean it will cause more damage, that's not necessarily the case. It's assumed you're attacking with both hands, yes. But you don't get extra attacks for that (unless your character is a Monk).

NWN1 is DnD 3.0
NWN2 is DnD 3.5

This is the best online resource I've found for 3.5 material. Had it open in another window when I was first archive binging Order of the Stick many years back ^_^ Multi-classing for one or two levels is commonly called "dipping". And yes, it can make a lot of sense to dip. Spellcasters, however, really suffer if you slow down their progression so it's harder to justify for them. Particularly at high levels, spellcasters are just going to be spamming spells non-stop in combat so it's not like they even have time to use other class abilities. In principle, yes this is how it works. In practice the amount of XP you earn is elastic in some cases (ie, a higher level character earns reduced XP for killing a weaker foe), so a Drow will actually get a bit extra and "catch up" a little. Still, the level penalty can hurt. At low levels this really sucks, particularly for spellcasters (including the cleric). However, once you reach the epic levels it's not quite as bad, and the drow's inherent spell resistance is actually quite insane. If you're willing to live with being an underdog for most of your adventuring career in order to be extra-awesome at your zenith, then go for it. Basically if you try to run past an enemy or cast a spell within his reach (or do something like disarm a trap; pretty much trying to do anything non-combat related during combat) then he gets to take a free swing at you. I've noticed the game can be a little bit trigger-happy on AoO. Yup, that is the case. I've never gotten parry to work well, however, and rarely put points into it. Freedom to hang yourself, indeed. On the other hand, some of the power-building can be absolutely insane.

Trying to post the rest of my original reply, as it wouldn't let me for some reason. So here goes: The game engine calculates initiative for each combatant, which determines who will act first, second, third, etc, during the combat round. Hope that helps a bit. I'm not certain, but I believe I read somewhere that sometimes creatures are acting in their own rounds and not in a universal round, but I'm not positive on that. I never really found the races that have more than a +1 level adjustment to be that enjoyable to play simply because they're so gimped for the low to mid levels. Later on, when you're getting to high levels it ceases to matter so much. But the first part of the character's career is painful and I never personally found the racial bonuses to be enough to offset it. As noted, AoO triggered if a character does a non-combat action while in melee range. Your character can only be awarded an AoO if you have a melee weapon equipped (you can't take an AoO with a ranged weapon or a spell). As well, you can only be awarded a maximum of 1 AoO per round (I don't think NWN2 implemented the feat that allows more than one per round. If they did, then disregard my last statement). The movement thing is if a character moves during combat and is in melee range, they will trigger an AoO unless they pass a Tumble check or have the Spring Attack feat. Parry is widely regarded as being a useless skill and a waste of skill points.

Regarding taking a level of fighter:

One thing to keep in mind is that there are XP penalties for certain kinds of multiclassing.

As I mentioned above, prestige classes are exempt.

If you have levels in 2 non-prestige classes, and one of them is your race's favored class, there is no penalty. If you have levels in 3 non-prestige classes, or two classes where neither is your race's favored class, then you will start getting XP penalties when one of them is more than one level higher than the other.

Thanks for your answers again

I am still at the beginning of the game, but I have 2 more questions.

-Can I see, how much the npc in my group like or dislike me?
Even in the few dialogues i had so far it went up and down a lot and you cannot please everyone.

-When I summoned the familar of the wizard in the tutorial, I could see its stats, skills and feats on the character screen. Now I have a druid in the group and she has her animal. But I can not control it or see its char sreen.
Is there a reason for this or is this a bug?

Familiars are different from animal companions or summoned creatures. They're the only ones you can control directly, because of their special bond with the wizard (note that if your familiar dies, you suffer penalties yourself). In earlier games, you could even speak with your familiars. When you control your familiar, you can actually have it cast any spells you have memorized that are at "touch" range.

Any other creature can only be given general orders, and not controlled directly.

For companion reputation, I think it's only in Mask of the Betrayer that you can see your influence on the companion's character sheet.