Khell_Sennet said:
Baldur's Gate - Why the hell couldn't you use the Wish spell to simply kill Sarevok?
Because despite the fact that Wish is a level 9 spell, it does have its limitations - both in the tabletop game and BG/BGII. Wish allows you to duplicate spells, undo harmful effects such as geas, remove injuries, afflictions or poisons, create certain magical or non-magical items, grant certain bonuses to your stats, revive the dead, transport travellers or undo misfortune (i.e., offer a reroll).
Trying to cast anything stronger may be perverted into 'letter of the law' or 'letter of loophole.' Wishing for immortality might turn you to stone or wishing for someone's death might transport you to their feet to kill yourself.