Hi, it's me again. I'm now facing Zuggtoy or whatever the final boss is called, and I'm again having some trouble.

Again, here's my party:
1. Dual wielding ranger (Longsword +3 and Masterwork Dao.)
2. Rogue with a crossbow.
3. Cleric.
4. Wizard #1.
5. Wizard #2.

Everyone's LVL 10.

I have buffed the ranger with every possible buff I have. The problem is, Zuggnotoy is still immune to every slash she makes. The wizards are able to do some damage with AoE spells, but I'm pretty sure I will run out of spells before getting the boss to even Badly Injured status. For example, the Wizards only have two Cone of Colds each.

What do I do? Any spells that can take away some of the boss' spell resistance? She succeeds in Reflex saves (or are they Will saves) against the spells quite often too, so while they do damage, with what spell can I make her fail those saves more often? And finally, any spell that could remove her immunity to weapons? I think the Ranger could beat her 1 on 1, if the hits actually did any goddamn damage.

That can be a hard, hard fight. Especially if you didn't do the stuff to destroy the golden skull.

Too late to get spell penetration and greater spell penetration feats. :(
Those feats plus a huge load of magic missiles (no saving throw) and empowered magic missiles were my main weapon.

I think she just has a huge load of damage resistance something like a stoneskin with 1000HP or so,
it'll wear out eventually if you can survive that long. I always had trouble with the survival bit.

Took me many tries the first time, the further attempts were with new content and level cap removed and thus much easier.

The thoughts that I had:

As far as dual wielding with the ranger, having a 16 dex/+3 bonus works nicely with light armor. You could wear a chain shirt for +7 AC. That's the equivalent of half-plate, if I'm doing the math right. Any medium armor you wear would get you from +6 to +8 AC, and any heavy armor would get you from +6 to +9 AC, (again, if I'm doing the math right), so it's not an amazing difference.

I've said it elsewhere, but I'll just mention it briefly. The rules for ranged combat are a little odd. You basically need a clear shot (not shooting over anybody's head), be 30 feet(?) away from the target, (unless you have point blank shot), and shoot something that's not in melee combat, (fat chance), to have no ranged attack penalties.

I like to take pot-shots at enemies as they close in on you before switching to melee, (with every character). You maybe get only 1 or 2 shots off, but if they hit, that's nice. Ranged is definitely useful against webbed or held enemies.

Zuggtmoy is only immune to +2 or lower weapons, so your Ranger should be able to do damage with any +3 weapon. As Jarmo mentioned she probably just has Stoneskin (or something similar) up, which your ranger will need to hack through before being able to do any actual damage to Zuggtmoy. Alternatively, you could also try to to dispel her protection, but since Zuggtmoy has a pretty high caster level it might be difficult to make a good enough roll on the dispel check.

Also, regarding spells, there are saves and there is spell resistance, which are two separate things. Spell resistance completely negates the effects of a spell, and in order to overcome it you need to succeed on the roll to overcome spell resistance (d20 + caster level + spell penetration feats). There are spells in D&D that can lower spell resistance, although I don't think any were included in ToEE. If spell resistance is the reason your spells are failing... well, you're pretty much out of luck. Saving throws don't (usually) fully negate spell damage, but rather decrease it and can negate some of the effects. Not all spells allow for saves, so if you're running into a problem with an opponent making their saves too often a good strategy is to focus on spells that don't allow for a save (as Jarmo mentioned, Magic Missile is a great choice for this reason in ToEE).

Also, the stuff she summons varies a bit from fight to fight,
from demons that can be tough as hell to the mushroom thingies that mostly block your way.

So after failing a few times you might have a lucky break.

If you have the craft magic arms feat, might be a good idea to burn some XP and create +3 weapons for ranger, rogue and cleric and see if you can't just hack her to death..

Thanks for the suggestions. Like I said she does have a Longsword +3, might be she just missed or rolled a really low damage roll because the hit didn't seem to do damage. I might try to see if I can craft the dao into a +3 too, though I'm just barely over level 10 so I might not have enough for the XP cost. Nevertheless, I'll try again once I'm back to my own computer.

If I remember correctly, that's the way the stoneskin-like damage reduction works, you first need to do a godawful amount of damage to wear out the protection, and only then you'll start to see the actual damage.

Her high spell resistance is a nuisance, I think I only got about half of the spells through with caster who had spell penetration feats, maybe only 1/3 of normal casters spells go through. Like DarrkPhoenix said, that's probably what's blocking the effect of most of your area effect spells, not just the saves.

There was one high level potential companion (sorceress demoness something) in the fire elemental node that can be of use in the late game (but then getting out of fire plane can be tougher than the end boss herself). Anyway, she was pretty dang effective, splashing out her huge load of magic missiles and such.

Alright. I came to think of one question: it was mentioned that she will summon creatures to aid her in the battle; I can confirm I've seen her summon a Glabrezu, a bunch of those fungi things and a couple of Voracs (or something like that). But will she run out of summons at some point? Technically, if I hack all her summons will she be not able to make anymore? Because that would make the part of wearing her out of her Stoneskin a lot more tolerable, if at the same time she didn't have a huge number of assistants trying to wear my ranger out as well.

Well, I managed to beat Zuggtmoy. However, I can't say there's anything proud about the victory.

During the early tries, she summoned a Glabrezu. I was able to charm the monster however, and it did very nice damage to Zuggtmoy. However, the bitch spawned sooooooooooo many fungi enemies, 4/5 of my party became completely overrun by them. I wanted them to survive, so I restarted the fight.

It came very clear to me that she would deploy them every time however, so I did what I think was the only way to beat the game... I charged with the Ranger, and everyone else ran to the complete opposite side of the map, where she couldn't spawn any fungi. This was after she had again summoned a Glabrezu, which I again charmed. It was very disappointing to see that this time the Glabrezu did nothing but stood there like a dummy instead of attacking, but Zuggtmoy focused on him and my ranger was free to perform hits unharmed. The rest of the party was away from any danger and doing absolutely nothing.

However, like I already explained, the hits didn't seem to do any damage. This was probably because the weapons weren't effective enough... so I put the Power Attack slider to the maximum of 10....and used a quickload every time the ranger made a round where she didn't impact the boss. If she did, I quicksaved. Rinse and repeat. A very, very sad tactic, I know. But like I said, with my setup I probably wouldn't have won otherwise. The hits then usually made 4-12 damage (and this was with Power Attack 10!) and since the boss had about 730 HP (don't know the sure number), the battle took about two hours. Consisting of mostly quickloading, since only a roll of 19 or 20 made an impact, plus there was some concentration check before everyy hit which had a 50/50 chance of fail.

Maybe these D&D games just aren't for me. With the exception of the final battle in Icewind Dale 2 (which for some reason wasn't that hard in my opinion), I've had immense trouble in every other final battle I've played in a D&D game (IWD1, BG 1 and BG 2 - especially the ToB expansion). It might be that I just don't know how to make an effective party with just the right skills. Might be better to stick to FPS and easier RPGs... but anyway, thanks again for the input everyone.

That's because RPG makers have this weird desire to make the end boss at least twice as hard as anything before it. Not just D&D, Final Fantasies are just as horrible.

NWN and NWN2 are much better in this regard. Well... a bit better anyway.

My best/worst victory in the game was taking down Zuggtmoy one of the times.
My solution? Cloudkills off level 10 casters. Cuts down the summons well, and you just stand off at the edge of the cloud and bombard with missiles, swapping to melee if needed.
I don't think I'd even destroyed the golden skull, but I may have kept the gems out of it... "Hey, I've got a great idea, lets fully power up the evil magic item! Oh noes its creator can use it!"

I also always make my 2 melee chars take at least one level rogue then if you flank your enemies they can both add their sneak attack to any and all damage rolls!

I almost always take at least 2 levels to get the Evasion as well.
But when looking to max stuff, take 4 levels instead, because of the way attack bonus works.

1st level of rogue, attack bonus doesn't increase
2nd level of rogue, attack bonus increases like you were a fighter
3rd level of rogue, attack bonus increases like you were a fighter
4th level of rogue, attack bonus increases like you were a fighter

5th level of rogue, attack bonus doesn't increase
6th level of rogue, attack bonus increases like you were a fighter
...

So 4 levels sacrifices one point of base attack bonus, the same as 1 level.
Lose on fighter feats but gain rogue feats and skills.

Tough to get whirlwind attack, but 2d6 extra damage when flanking is nice as well..

If you were going to do that, take 3 levels. You lose one feat and still get 2d6.

Probably the best powerplay option yeah.
Especially if you take 2 fighter/rogues and can specialize eg one to pick locks & disarm traps,
and the other to have the other rogue skills.