True Seeing does nothing about foes that are concealed. And Blind Fight increases your chance to hit enemies with Concealment from 50% to 75% -- literally a 50% increase in damage.

Actually, True Sight does negate the miss chance of Darkness. It makes Ultravision obsolete. (Although Ultravision is lower level and lasts longer, so it's still useful.)

However, MagicalMaster is quite correct that it doesn't do anything against other forms of concealment, many of which cannot be dispelled or purged. (If your character is even capable of such, which many aren't.) So it's still a rather important feat to have.

Is "Weapon focus" feat any good? I refer not so much to the +1 attack bonus (which I think isn't really worth the feat, unless it's needed as a prerequisite to unlock something else, e.g. Champion of Torm class), but, quoting from Wiki, "This feat is commonly used to influence the type of weapon generated as loot in specially designated containers. (The assumption is that a player will not focus in a weapon that the player would rather not acquire.)" - does it make a big enough difference in which weapons are acquired to be worth taking? (I'd guess the containers in question are supposed to contain some sort of magic weapons, usually?)

I'm asking, since I'm thinking to build that ranger/rogue with Improved Critical (and its Epic follow ups) line of Feats, which have to be taken with specific weapon in mind, but to be able to do that and take Weapon Focus (in two different weapons, e.g. Long Sword for main hand and Short Sword for off-hand) I'd have to start with the two starting Feats of a human taken towards it, so for example Power Attack and Cleave (where I'd otherwise rather take the level 1 only feats influencing saving throws I think, like Luck of Heroes and Strong Soul or so).

So, is Weapon Focus worth taking with the above in mind?

It depends.

The default random-loot system does take these feats into account, but many modules, especially the better ones, don't use this system and instead hand-place their own items in places where they make sense.

That said, a simple +1 attack bonus does have a much bigger influence than you'd think at first sight. I used to think the same as you, but then I got in a discussion with someone on this forum and actually did the math and it turned out they were right and I was wrong: the extra hit chance makes a much bigger difference to most builds than you'd think, often bigger than for example feats like Improved Critical and Weapon Specialisation.

Take for example a typical level 20 fighter who has 4 attacks, 26 STR and a +4 flaming greatsword. (Average damage: 26.5) He attacks something he has an 80% chance of hitting on his first attack. (And 55% on the second attack, etc.) The average damage he'll deal per round is 49.489, if you account for critical hits.

If he takes Weapon Specialisation, his damage improves by 2 points for every hit, giving an average of 53.224 damage a round.

If he takes Improved Critical, the extra critical hits increase his average damage to 53.861 points a round. Better.

If he takes Weapon Focus, all his hit chances go up and his average damage improves to 55.385 points. As you can see, Weapon Focus actually makes the biggest difference of them all!

Taking all three feats, of course, is best: average damage goes up to 64.98

(It will vary in actual gameplay, of course. Improved Critical is useless when facing the Undead, and better when you use a weapon like a Scythe or a Rapier. Weapon Specialisation is better when facing foes with high Damage Reduction, or when using a low-damage per hit weapon like a shortsword. Weapon Focus is better if you have a really strong magic weapon or sneak attacks or other ways of further improving your damage-per-hit.)

Well, that depends. As illustrated, the feats make a considerable difference in combat, but having to take 2 is a pain in the behind. If you're going to take the improved critical line of feats anyway, you might as well take Weapon Focus too. But honestly, I might just decide not to bother with either.

Also note that the epic improved critical feats aren't necessarily the best idea to aim for: Overwhelming Critical is fairly useless. Devastating Critical is immensely overpowered, but has requirements so steep that you're extremely unlikely to ever get it in single player mode. There just aren't enough modules that take you up to those levels.

And environments that do (Like the Aielund modules, or many online persistent worlds) tend to disable the feat anyway because it's so overpowered. Luck of Heroes is a great feat. Strong Soul not so much. I'd rather just take Iron Will to boost my will save. Or drink potions of clarity until I can save up for an item that makes me immune altogether.

So, if not taking the Feats toward Imp. Critical and follow ups (which means I might also not take Power Attack and Cleave/Imp. Cleave, since somewhere earlier it was posted, that Cleave is somehow bugged when dual wielding?), that frees up all those feat slots - what would you take then, if talking about combat-oriented feats? (Other options I was considering prior to that were skills oriented ones, like Skill Focus in f.ex. Open Lock, or Epic Reputation at level 21+, and maybe the Feat improving the Reflex save, but as I'll be unlikely to ever reach level 40, when I'd pick 10th level of Rogue, and Imp. Evasion feat, I guess it's better to skip this one?)

Also while discussing feats, since I'll probably make a barbarian for the modules which came with NWN (one for all of them), do you think that, starting with Strength 16, I'll reach the level allowing me to pick the Imp. Critical line of feats? (with one weapon this time, probably a Greataxe - if I manage, maybe also with Weapon Focus in it, in light of what you told me)

Skill improving feats generally aren't very useful. In fact, there's hardly any need to increase Open Lock past a dozen or so ranks, since you can easily buy powerful Thieves Tools at higher levels, and/or get equipment that boosts the skill. And at high levels you'll never fail a persuade or bluff check if you just invest normal skillpoints into them, so epic reputation is pretty much a waste.

There are exceptions: bards can benefit from Epic Skill Focus Perform at epic levels, for example, and in online play taking (epic) skill focus on stealth or spot based skills can be vital if you want to use them. Not relevant for single player, though. Epic Skill Focus: Concentration can also be nice for wizards/clerics and the like.

Good combat feats include:
* Luck of Heroes: good save boosts
* Knockdown: the best active combat feat. Makes many fights MUCH easier. And knocked down foes can be sneak-attacked. Take this one.
* Improved Knockdown. Not as important, but it will let you knockdown big foes like dragons and giants. Recommended if you have sneak attacks.
* Blind Fight. As discussed earlier.
* Toughness. More hitpoints = good.
* Dodge: More armour class. Only works against one foe at the time, though.
* Power Attack/Cleave/Great Cleave: Helpful, though not THAT helpful. It's very good at low levels, and the improved version is pretty good at high levels, especially if you have few attacks per round. (i.e. you use a two hander or shield instead of dual-wielding) Power Attack isn't very good on its own, though.
* Expertise: Situational, but very good in some settings since it can make your character a great tank. Not really necessary in most single player modules, though.
* Weapon Focus/Improved Crit/Weapon Specialisation: As discussed, they're all helpful. But if you want to use multiple weapons you may not be able to afford them.

Not so good:
* Disarm/Improved Disarm: Not actually all that good, since for some reason many foes are immune even when they shouldn't be. (You can't disarm stock orcs, for example.) Which is a shame because it's a lot of fun to use.
* Other save-boosting feats: You can get much bigger bonuses from items, generally.
* Anything to do with parry. It's bugged.

If you're an archer:
* Called Shot: Not as powerful as Knockdown, but it works with ranged attacks, making it great for archers.
* Point Blank Shot/Rapid Shot: If you're an archer.

At epic levels:
* Epic Weapon Focus: if +1 attack bonus is good, +2 is great.
* Epic Weapon Specialisation
* Epic Prowess: for the same reason weapon focus is good
* Armour Skin: Armour class is just as important if not moreso than attack bonus.
* Great Strength (or DEX if you're Dex based): More hit chance, more damage
* Improved Sneak Attack: Only available if you're a high level rogue, but it can add up.

It's somewhat bugged when you have 4 or more attacks. (Which happens earlier when you dual-wield.)

You can never attack more than 3 times in a round, (except when you have Cleave or are making attacks of opportunity) so when you have 4+ attacks, your attacks start occurring in so-called "flurries" where multiple attacks happen at once. So a character with 4 attacks will get one "double" attack and then 2 normal attacks. 6 attacks will get you three "double" attacks, 7 will get you 1 triple and 2 double.

The problem is that if the first attack on a "double" flurry kills the target, the cleave attack gets aimed at the already-dead guy. Which is kind of useless.

If you have Great Cleave, this problem disappears: you simply get a second cleave attack on the next enemy after the useless cleave against the already-dead guy.

So: either take both Cleave and Great Cleave when you hit higher levels, or take neither.

A few notes:

* The expansion sare NOT meant to be played with the same character you play the original NWN campaign with.
* The original NWN campaign gets your character from level 1 to 16-18. It's also not very good.
* The first expansion (Shadows of Udrentide) is meant for a new character and takes you from level 1 to 12-14. It's fun enough and has some clever dungeon design.
* The second expansion (Hordes of the Underdark) is meant to be played with the character from Shadows of Udrentide and takes you up to level 25-27. It's pretty good: most people consider it by far the best of the lot.
* You can take Devastating Critical as early as level 21, if you're a Half Orc fighter/something who starts with 20 STR or a fighter/bard/RDD who gets strength boosts. Or both: a half-orc Red Dragon Disciple with fighter or (preferably) Champion of Torm levels. You then have to take an even fighter level as your first Epic pick. (Thereby getting 2 feats, letting you pick both Overwhelming and Devastating Critical.)
* So yes, you could get it in the Hordes of the Underdark campaign if you plan ahead for super-high STR.
* But honestly, Devastating Critical isn't much fun. Either it works and you kill everything you touch, or you're facing crit-immune stuff and it does nothing.

I generally agree with everything Jason said, just mentioning that to show it's not just him.

As a general rule of thumb 1 AB is a 10-15% damage increase...and if we look at his numbers (49.489 -> 55.385) we see that's a 12% damage increase, which falls within the expected range. AC is the same but in reverse (you can take 10-15% more attacks).

One thing I do disagree with...

The problem with items is that they cap at +20 (this goes for bonus from Spellcraft and buffs as well, all part of the same pool). Which means if you're a level 40 Fighter with 16 base Will at level 40 (10 Wisdom, 6 Will pre-epic, 10 bonus saves from epic) your maximum will save with no feats is 42 (+6 Will from +12 Wisdom gear and +20 saving throws). Spell DCs from PCs alone can hit 45, abilities from enemies could go even higher. In this context you have a 15% chance to fail the 45 DC check. Luck of Heroes would make that a 10% chance but Iron Will would make it a 5% chance. Obviously Luck of Heroes gives a +1 bonus to Fortitude and Reflex as well...but my point is that the save-boosting feats allow you to target your weakest and/or most important save(s).

If you're playing a character where Luck of Heroes is worth taking, then taking at least one of Great Fortitude/Lightning Reflexes/Iron Will is almost guaranteed to be it.

Hm. Is there some reason I don't know of, why dual wielder should go for Dex instead of Strength?
(my plan so far is to put points in Str, and get Dex from items, especially all the monk gear useable with Use Magic Device)

No, but typically a DW won't be as strong, since you need at least 15 dex natural, to dual wield effectively, or wear light armor as a Ranger, in which case you need Dex for armor class. Also it goes without saying that if you are DW'ing, you aren't using something like a Greatsword, which packs significantly more punch at low levels than one-handed weapons.

It isn't just strength/damage. A DW will need feats Ambidexterity, Two Weapon Fighting, and ITWF. Which makes spending feats on Power Attack/Cleave comparatively more expensive.

The cost of cleave is higher and the returns are lower for a DW character.

So... is something like starting with Str 14 and Dex 14, putting points into Strength, and getting Dex from gear, a bad idea?

No, that's a fine idea. My ranger characters tend to do that.

You won't have super-high armour class, because you'll mostly wear studded leather with up to 18 DEX for a total of 7 base AC. But that won't make a huge difference: a full-plate wearing fighter can get up to 9 base AC, which is only 2 points more. A full DEX build will get 8 when wearing leather if they have at least 22 DEX, 9 total if they wear padded armour and have 26+ DEX, more if they wear cloth/monk robes and have even more DEX, but that's only a factor very late in the game.

You compensate anyway by getting Tumble, which will actually give you as much/more AC than a typical DEX based pure ranger.

The biggest weakness is that your armour class will be lower at low levels, when you can't get your DEX up yet.

It's OK if you like mediocrity. What kind of character?

I would never start with less than 16 in my primary stat, 17 if I can swing it.

If +1 attack, from Weapon Focus is such a significant bonus, then +1 attack, and +1damage from starting with higher strength, even more so.

Again, at low levels all these bonuses are even more critical, and you are not likely to have any gear to boost them for several levels.

A typical start for my Strength oriented fighter Rogues:

STR: 17
DEX: 14
CON: 13
WIS: 8
INT: 14
CHA: 8

Human: (Quick to Master)
01: Rogue(1): Power Attack, Cleave
02: Fighter(1): Weapon Focus: Greatsword
03: Fighter(2): Toughness, Knockdown
04: Fighter(3): STR+1, (STR=18)
05: Fighter(4): Weapon Specialization: Greatsword

At 5th level I have total AB of +9, and average damage of 13/hit and cleave and knockdown. I find this MUCH more effective (and fun) than dual wielding at lower levels, which can be downright painful in comparison.

Well, as mentioned, I put skills over combat initially, so I want a lot of INT (and since I don't like negatives, even if that's silly, I'll want my stats to be 10 minimum).

So, starting stats:
STR: 14
DEX: 14
CON: 12
WIS: 10
INT: 16 (I'll only have 4 rogue levels prior to 21, so every skill point saved up at ranger level will make a difference).
CHA: 10

And current plan is to only put points into Strength.

Though since I'm ignoring the spellcasting part of a ranger, the idea to pick a barbarian instead crossed my mind (so either a two hander or weapon + shield instead of dual wielding), since that'd also mean 4 skill points a level, plus more hit points, plus damage reduction, plus medium armor early on (before I'd get all the Dexterity gear).

I kind of like the idea of a ranger though, logic and math be damned.
(and since I might make pure barbarian for official campaigns, I'd like something different here)

With going for a lot of Int, it also did cross my mind to become a Wizard, but only two skill points a level (+int bonus), and besides, I don't feel like playing a spellcaster, that's why I abandoned the idea of a cleric for barbarian for official campaigns.