As far as I’m concerned, the Wizardry and Ultima series still represent some of the best Role-Playing Games ever made. The nice thing about computer based RPGs was that you could expand and modify them to some extent, even if that was not officially supported. You could do it the hard way with something like a disk sector editor or you could use third-party tools made for the purpose.
This particular ad from 1984 is advertising two different tools from a company called MagicSoft. The first is called “Wizard’s Toolkit #1” and allows you to edit Wizardry I, II and III by adding new weapons, monsters and certain other items. These games were available for multiple computers and it isn’t clear which computers may have been supported.
The second tool is called “Exodus Construction Set” and was made to modify Ultima III: Exodus. From the description, it seems to allow an even more extensive level of editing. However, it apparently was only made for the Apple II version of Ultima III.
A third tool, Wizard’s Toolkit #2, is mentioned as forthcoming as well though I don’t know if it was ever released. Some developers would eventually release official tools for this kind of editing but in 1984 this was pretty new territory.