I'm going to be running Rise of the Runelords soon for some friends who've, in general, never done any tabletop gaming. Two of our players (who will only be attending some of the sessions) have experience, but the other four (yes, it's a party of six) have absolutely no experience, at all.
The fact that my party will be six players is my reason for posting. I'm aware that RotRL is designed for four players, and whenever my two experienced players aren't attending, I'll be running the campaign essentially as-written. I would like to ensure that it maintains its difficulty when all six players are there.
While thinking about this, something caught my eye. Nualia's group is set up almost as a standard adventuring party, and it seemed to me that it would be fitting if, at some point, her party and the PCs would duke it out.
My question is, if I have six players during said combat, should Nualia's group also have six members? Obviously, this would require both Tsuto surviving the Glassworks and the addition of essentially a homebrew character, but I'm wondering two things. Would this unbalance the encounter too heavily against the PCs? After all, most of Nualia's party have at least four class levels, and the one who doesn't (Bruthasmus, I believe?) is still a CR3. Would the addition of the other two members make a TPK or something close likely?
If an additional member would simply serve to make the encounter more challenging, but not unbeatably difficult, my second question is this: What class should the sixth member of Nualia's band be? My own party consists of a Fighter, a Ranger, a Sorcerer, a Rogue, a Cleric, and a Druid (the latter two being the two that may not attend every session).
Any advice would be great.
