IRRC last time I was in the mines it was quite easy. But it's been like five years, so I might be wrong.
I've started a new party with a mage. I'm running aroud the countryside cleaning some areas there before going to Naskel. Just got my first lvl 2 spellslots, a pity there are no usefull lvl 2 spells (I'm an invoker. I can't have conjugationspells <img src="/ubbthreads/images/graemlins/cry.gif" alt="" />).
I've allso noticed how extremelly well it works to just lure one opponent to your group. I have three archers, me (with a mighty sling), Iomen and Kivan and Jaheira and Khalid, so I usually take Khalid and lure them to my party. All the way back to my party, so the monsters have to run a bit while my archers spray them with arrows (ok, not me. After all, I'm a mage). That way they're hopefully soft enought when they get close enought for Jaheira and Khalid to attack. I'm looking for another meleefighter though...
Übereil