Neverwinter Nights 2 completely blew away NWN 1. It's story was far more compelling, I found the original's story to be a snooze fest. The only thing that was bad about NWN 2 was the brain dead AI of your companions, but that was solved by taking a direct control in combat. Too bad Obsidian didn't go with turn-based combat.

In terms of campaigns, NWN2's OC is significantly better that NWN's OC, but is still firmly mediocre. NWN does a bit better with its expansions, but I never felt that either of them were really anything to write home about. On the other hand, the Mask of the Betrayer expansion for NWN2 is excellent, and the Storm of Zehir expansion, while a bit different (you fully create your own party without a main character, similar to the Icewind Dale games) was also quite good in my opinion.

That said, I'd still consider NWN the better deal overall, simply due to the quality of user-made modules available for it (The Prophet series, The Ailund Saga, Tales of Arterra, excrucio eternum, and the list goes on and on). If you haven't already played NWN then get it, learn the basics of how to play, then start playing through the user-made modules.

I felt the same way as well until playing some of the user made content. Specifically, the Shadowlords and Dreamcatcher modules are what finally drew me into the first game.

As for the second, I was put off by poor performance and never really went back. It's probably high time I gave it another try, especially Mask of the Betrayer.

Can I play MOTB without the other NWN2 games?

It requires the base NWN2 game, but not Storm of Zehir.

Sorry for being unclaer, but I meant in terms of story and characters. As in, can I just jump into MOTB without having played NWN 2?

The events in Mask of the Betrayer occur right after the end of the main campaign. That said, there are few returning characters and the plot takes a pretty steep turn so you'll probably be fine if you just read a plot summary or something. Just be prepared to create a level 18 character right in the beginning.

Mask of the Betrayer continues the story of the main character from NWN2. The beginning of MoTB kind of spoils the canonical (i.e. "good aligned") ending to NWN2, but, if you don't mind that, it shouldn't be necessary to complete NWN2 first to enjoy MoTB.

Reresh Edit:
Ninja'd by AlKIim, but we said essentially the same thing.

NWN 1 OC was pile of trash but the user modules kinda made up for the terrible campaign. NWN' 2 was significantly better and MoTB was absolutely fantastic.

I've only ever played NWN1 and its expansions in a 2 player LAN game with my brother. The main campaign is pretty good but like a few Bioware titles I've played I find they only seem good on the first playthrough after which they get a bit tedious, for example, I've completed mass effect 2 about 6 or so times with different classes and male/femshep combos whereas dragon age 1 I completed it then got about halfway through a second playthrough before getting bored. I hope GOG can get the rights to a complete edition of NWN2, a lot of people here say its good and I've waited for years to get it without the wacky securom issues.

I'm playing through the NWN1 OC as a human fighter / weapon master with a greatsword...

...it's hilarious:

*great cleave*, *great cleave*, *great cleave*, *great cleave*, *great cleave*, *great cleave*, *great cleave*, *great cleave*, *great cleave*, *great cleave*, ...

------------------------------

NWN1 vs NWN2:

Story: NWN2...

Gameplay: NWN2 (I preferred the feel of combat in NWN1 - the second game only gets the edge by having full party control)

Graphics: NWN2 (the textures and lighting/shadows in the first game still look pretty awesome, shame the models haven't stood up so well)

Sound: Tie - both games sound pretty good. NWN2 has more voiced dialogue, but also re-uses quite a bit of the NWN1 soundtrack, which I found kind of annoying.

Interface: NWN1 (various things in NWN2 seemed like a step backwards from the first game - the right-click menu in particular. 1x1 tile inventory avoids the "inventory Tetris" problem but sometimes makes it hard to "read" inventory contents quickly)

Technical: Tie - both games have issues, thankfully they're not game-breaking.

As others have mentioned MotB occurs right after the NWN2 campaign, with the same central character. However, the location is completely different and only one of the characters from the OC makes an appearance (and a rather brief one at that). You'll miss a bit of backstory regarding a certain sword and the events leading up to how your character got into the position that he starts the MotB campaign in, but there's enough information provided to quickly fill in enough of this to make good sense of what's going on.

Bottom line, if you're not particularly interested in playing the OC and just want to jump straight into MotB you can do so without missing out on much.

Play darklands instead.