The engine in NWN2 is a wondrous enigma. For starters, the advanced page of the graphics tab doesn't even have all of the advanced options - some must be reached from outside of the game entirely by editing the INI file. Second, the game has a curious quality relationship - high settings run poorly, and low settings run almost as, if not equally, poorly.
With that said, let's take a look at what you're getting when you sacrifice a few FPS. We've taken a few pictures at high, medium, and low settings - but I like to be honest - aside from the spell effects, nothing about these graphics are truly high except for inexplicable overhead.
Because of the camera angles and level design, there was not an area that actually showed both water and a decent view simultaneously. This may be on purpose - the water effects are quite nice, and if they are produced similarly to other effects then the engine might just grind to a halt. Therefore, we opted to illustrate the most taxing scene you'll see often in the game - an outdoor scene from the Neverwinter Market District, with no water.
Below, you can see the two menus of settings choices.
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High Settings
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As you can see, the game is alright looking, but far from beautiful. You can see that the draw distance is not exactly wonderful even at its highest setting, but much of the other detail is certainly attractive enough. Water at this setting looks quite good, and as I mentioned it's one of the better effects in the game. Despite there being a 'bloom' setting and many loading screens pictured with HDR, the actual game lacks good implementation of either effect. At this setting, my 7950 GX2 ran the game at around 25 FPS according to the in-game counter.
Medium Settings
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At what would be 'medium settings,' the draw distance is cut in half, bloom is turned off, and shadows are reduced to medium levels. The draw distance has very little effect, but the shadows have a tremendous one. Frame rates will increase noticably at this setting, because environmental shadows turn off - however, it's easy to see how much of a negative effect this has on the game's already limited atmosphere. It also doesn't change the constant hitching in the game that is caused by the particular way the engine handles texture files. In many respects, this can be more annoying than high settings, where at least things run at a predictable slow pace.
Just-Plain-Fugly Settings
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When set down to the lowest settings (at least as far as in-game options), the majority of visual appeal in the game disappears. Character models look almost impressionist at points, because shadows are used in higher modes to obscure the game's lack of high texture detail in models. In the lowest setting, even these disappear, leaving you with a rather cold, over-bright world. Frame rate differences between this and the 'medium' settings are almost non-existant, so there's little reason to drop down to this.