I was thinking about picking up Haer'Dalis for an evil party sort of thing for my sixth and I was curious how the song improve with levels. I'm pretty sure that it effects luck, but does the number that it effects increase with level and if so, by how much at what levels? --- Life is uncensored. Prepare to blush.
Haer'Dalis is a Blade and a stated limitation of that kit is that the bard song does not improve beyond the basic song available to 1st level Bards. Until you get the Enhanced Bard Song HLA that is.
However, I've been looking around and I can't find any concrete info on what the basic Bard Song actually does - best I've found is that it probably adds +1 Luck for every 10 levels (+1 thac0, +1 saves, +5% thieving skills) and boosts Morale in the same way as the Resist Fear spell. I've also seen it said that the luck bonus is bugged and only the morale bonus is actually implemented.
Hm the description of luck is very loose I think. In IWD2 it shifts all your dice throws up one number, so there it is a very very useful stat. It makes characters crit more (since a 19 will be shifted to a 20 and a 20 will stay 20) and eliminate critical misses. Also I think damage rolls will be higher, so a magic missile with its 5d6 or something like that will get +5 damage for every 1 luck.
The question is, does it work like that in BG too?