Theoclymenus: Why oh why oh why get rid of the best combat system ever : the D&D system ? This was the meat of the IE games and was what really made them great, though lots of other things also made them great.
Coelocanth: Because it's a licensed system and they didn't want to have to pay the IP holders to use it (and would have been forced into 4e D&D rules if they had).
I love the D&D system myself (started playing way back in 1977) but I wouldn't say it's the best combat system ever.
Well I'm certainly no D&D expert but it's hands down the best combat system I've ever experienced in an RPG. There are all these otherwise "beautiful" RPGs (TES games, The Witcher etc.) but because the combat is simplistic and primitive in these games I don't want to play them. What the IE games did was to combine an incredibly engaging combat system (which actually worked rather beautifully with levelling up and general character development) with lovely hand-drawn art, beautifully realised characters, fantastic dialogue, all-round great writing and amazing atmosphere. I just cannot understand why this formula was dropped, unless it had something to do with the split between Bioware and Black Isle Studios ? I really don't know the answer, not being part of the industry, but for me every RPG since the IE games has been poor - especially Bioware's mysteriously much-vaunted stuff.
Edit : It's a shame - and also a disgrace - if it all had something to do with money. I know that the last IE game - Icewind Dale 2 - used a different D&D ruleset (3rd edition ?) than the first four IE games used (2nd edition ? I don't know any of this stuff, I just played the games and loved them). Well, Icewind Dale 2 was still awesome, though the new rules took a bit of getting used to. But to abandon D&D rules altogether - WHY ? There is no better set of rules, for combat at least, that I've encountered in a game. Why did Bioware go down the "dumbing down" route after this and is Pillars of Eternity just going to be more of the same dumbed down rubbish ? I already know that it is, based on very little research, so I shall not be bothering with it.