A large number of adventures and supplements were published for Classical D&D over the years. Most are usable with any version of Classical D&D without major modification and can easily be used with Original D&D or First Edition AD&D with only a little effort from the gamemaster. The major exception to this is the Immortals modules which really only work well with the Immortals Set of the BECMI version of Classical D&D.
For the most part, TSR adventures for Classical D&D were divided into series based on rules set. B-series modules only needed basic Set rules, X-series modules required the Expert Set, C-series modules were for use with the Companion Set, M-series modules were for use with the Masters Set, and the above-mentioned IM-series modules were for use with BECMI Immortals Set.
Basic Set Adventures
These adventures were designed for use with the Basic Set — character levels 1 to 3.
- B1 – In Search of the Unknown
- B2 – The Keep on the Borderland
- B3 – Palace of the Silver Princess
- B4 – The Lost City
- B5 – Horror on the Hill
- B6 – The Veiled Society
- B7 – Rahasia
- B8 – Journey to the Rock
- B9 – Castle Caldwell and Beyond
- B10 – Night's Dark Terror
- B11 – King's Festival
- B12 – Queen's Harvest
These adventures were not specifically designed for one particular set of Classical D&D rules.