The first adventure, at least, can be played with almost no changes whatsoever. I don't have the magazine and book both handy, but I ran the first adventure from the magazine with 3.5 characters with no problems whatsoever (except for the TPK soon after they entered the Malachite Fortress). At any rate, there are few spellcasters, and I don't think any of the monsters changed in any significant way. Hope that helps.