Players made real decisions and DMs were trained to expect the unexpected.

In the old-school, plotting was mostly left to the DM and stories grew spontaneously in game play. These were the days of sandbox designs, before adventure paths took over and railroaded players into pre-determined stories. I hold a classic to be a module published between the late ’70s and the middle of ’83, with a few exceptions falling outside this window. Here are the classic D&D modules ranked from best to worst.