Will you be able to play Adventure one of Skull & Shackles with the Runelords base set or will you need to buy the Skulls & Shackles base set also?To be pedantic, if you have Adventure 1 of Skull & Shackles, then you will already have the Skulls & Shackles base set :) Adventure 1 will be included in with the base set, it will not be available separately. Adventures 2 to 5 will be available separately.
But answering what might be your intent, no it shouldn't be possible to realistically play without the base set because the base set will include most of the cards required to play. For example, there will be new location cards specific to Skull & Shackles, new Henchmen, new Villains and so on. Without these you will be not be able to construct the new scenarios, if you use the RotR weapons, spells, armour, items, allies and blessings then it will be a real hodge-podge mess IMHO.
Thanks!
Thats pretty much what I figured, and it definitely makes sense... but I wanted to check just in case. :)