There are a great number of little details left out in BG2, as the game was finished in something of a hurry, and BioWare simply didn't have time to go around implementing every little thing (or even some of the big ones). 2 of the snippets that got left behind were "A high Wisdom score improves your odds of making your Saving Throw against mind-based spells, such as Confusion and Feeblemind," and "A high Intelligence score can allow your character a chance to Dispel enemy Illusionary spells, just by looking hard enough."
But one of the details that DID get through was "Dwarves and Halflings get bonuses to their Save vs. Death and Save vs. Spells, if they have a high Constitution score." The specific details are in one of the *.2DA files.....I forget which one at the moment.
The link in my sig will take you to a very thorough guide of BG2; Chapter 4 has the Saving Throws for each of the various classes (albeit only for the first few levels; I'll have to remedy that when I update the site). As has been said earlier in this thread, Priests get a bonus to their Save vs. Death, and Wizards get a bonus to their Save vs. Spells. But what's
most important is that
Warriors have the best Saves, because their Saves
improve at a faster rate than anyone else's. And tacked on to that, Dwarves, Gnomes, and Halflings recieve bonuses to their Saving Throws, depending on what class they are.
It's a complicated game. Did you really expect an explanation of Saving Throws was going to be
simple?