NWN's original release brought D&D 3rd Edition rules to CRPGs – The 4 BG & 2 IWD games had previously used variants of AD&D 2nd Edition – and as such it therefore brought some radically different approaches to game play and character generation. Like many CRPGs it initially had numerous bugs, but these were regularly acted on by Bioware who have supported the product consistently and efficiently. Not all bugs have been resolved but the ones that remain are minor and there is plenty of community support to customise and patch these with free scripts and hak packs.
Two additional expansion packs (Shadows of Undrentide & Hordes of the Underdark) mean the game programming has been greatly expanded (in all areas) and the depth of play, the ability to become immersed, is excellent. With extensive online, multiplayer, & DM capability (compare NWN2 which is initially weak in this area) there are thousands of hours of satisfying play from replaying the Official Campaign, downloading 6 ‘premium’ and unlimited free modules from the internet. And that’s before you even look at the toolset to start writing your own modules; or joining an online game! This is a true game of infinite possibilities.
If you are considering NWN or NWN2 I strongly suggest NWN over the latter at this time (i.e. prior to mid-2007). In fact I suggest you consider the Platinum Edition which includes the 2 expansion packs mentioned above (the Diamond edition includes 3 of the 6 ‘premium’ modules including 2 recommended ones). Although the graphics are a little dated now the overall game play is very compelling and you will get excellent value for money in the long-term. The original NWN (Neverwinter Nights) will always have a special place alongside Baldur's Gate I & II in the CRPG Hall of Fame…