So I like understanding the math in the background of combat, but I'm having trouble understanding NWN 2 and ice wind dale 2. I know in baldurs gate the attack roll is your thac0 minus their armor class and if the die 20 is higher or at that number it's a hit.

Can someone explain to me the variables in Nwn2? Like what is subtracted or added? Please explain simply with an example or too I would greatly appreciate it!

Google 3.5 edition D&D rules. There is a wealth of information on it.

I did, I don't understand it

The reason I said to Google it is because it's actually quite complex. I will do my best to break it down for you...

- Each class has a BAB (base attack bonus) - Low, Medium, High. E.g. Wizards are low, Rogues are Medium and Fighters are high. This is the basis for any attack role.
- A players actual attack role is based on modifiers applied to this figure (AB).
- For Melee (assuming no Weapon Finesse), STR bonus is added to the role. E.g. STR of 16 adds 3 to the role.
- For Ranged (assuming no Zen Archery), DEX bonus is added to the role in a similar fasion as above.
- Certain feats like Weapon Finesse an Zen Archery modify what source the bonus is - Zen Archery uses WIS, Weapon Finesse uses DEX.
- Any enchantments to weapons or spell effects are also added to this role.
- This combined role has to be higher than the opposing player's AC (Armour Class). Although you are guaranteed a hit on a 20 (and a critical threat roll). You are also guaranteed a miss on a role of 1.
- You roll a D20 (20 sided dice) for Attack roles.
- The opposing player's AC also has modifiers from spells, Armour, DEX, (and additionally WIS in the case of a Monk).
- You then have the damage roll and Critical hit role to consider after this attack "hits".
- There are additional things to consider here too - like concealment etc. It can get messy!

...That's as simple as I could make it without writing pages upon pages of info. Google is still your best bet there. If there is a particular part of this you do not understand, I will try and help if I can.

I haven't played either of those games, but I know they're both based on D&D "version" 3.5, which I have played. Basically, it's (1d20 + Base Attack Bonus + STR modifier (or DEX modifier, if it's a ranged attack...usually) + any size modifier (+ range penalty, when applicable, for ranged attacks)) vs. your opponent's AC (10 + DEX modifier + armor bonus + shield bonus + size modifier), where a natural 20 on the attack roll is an automatic hit with the possibility of also being a critical hit. As long as your attack roll + modifiers equals or exceeds your opponent's overall Armor Class, your attack is successful, and you deal damage (which is based mostly on the weapon itself, generally modified by your Strength). However, there are a ton of things which can come into play to modify attack, AC and damage (3rd Edition basically being a game of exceptions to rules).

In other words, in 3rd edition, higher numbers are better in both attack AND defense, unlike earlier editions' rules.
This page of the D20 SRD explains some of the variables in somewhat more detail.

Thanks a lot guys that's some good info I can understand. So I want my bab and AC to be high. I just got done with another baldurs gate play through where ac and thac0 were supposed to be lower so I kinda got confused.

Another question I have is why is it saying in my character description that I favor/proficient with a mace? I chose Tyr as my deity and that god prefers long swords. My background is paladin natural leader

Unfortunately, dieties in the original game were never really implemented. NWN 2 fixes this, but in NWN 1 it's literally just a text field that does nothing in terms of class Weapon Proficiency, Cleric domains etc.

Where exactly do you see that your character favors mace and what exactly does it say? Naturally Paladins are proficient with all simple and martial weapons which includes maces. My guess is that you chose mace as your favorite weapon so you recieve a +1 for it. If you can write it exactly or better take a screen shot of that page we can answer better. I just created a paladin in NWN2 and couldnt find an other way of creating such a thing.

Clearly not enough coffee happened there. Ignore that bit in bold. I shall go back end edit it.