All the existing classes in 5e are available for Blackmoor campaigns. More will be said about the role of the Wizard's Cabal elsewhere in the site in relation to Sorcerers and Warlocks.
This section details three new base classes that have been added for play in a Blackmoor campaign. They add new flavor and options that fit within Blackmoor’s core philosophies and organizations. Much of the supporting materials throughout the rest of this book reference these classes. Be sure to at least peruse them lightly even if you do not plan to select one for play at this time.
Quote above taken from Dave Arneson's Blackmoor copyright 2004 Zeitgeist Games. For additional details, pick up a copy of the source book.
New Character Classes