Everything old is new again, again.
Wizards of the Coast in conjunction with Drive Thru RPG just opened the new D&D Classics website, home to some 80 previously out of print Dungeons & Dragons rulebooks and adventures available for purchase as pdf files. Each book was freshly scanned, cleaned up and the text is fully searchable. You'll find a treasure trove of resources for every edition of D&D from Basic to 4th edition.
To celebrate, Wizards is giving away a piece of history: B1 In Search of the Unknown is free to download for a limited time (get it HERE). B1 was the first stand-alone adventure module published by TSR. Game designer and editor Mike Carr saw a need for an introductory adventure that introduces novice gamers to the art of dungeon mastering. Unusual for a beginner's module, the adventure actually requires a lot of work before it is ready to play. Shannon Appelcline, game historian and author of Designers & Dragons, says this:
The actual adventure leads off with advice about running adventures, but its introductory nature goes beyond that. Designer Mike Carr purposefully included a number of features that he thought players should expect in dungeons, like one-way secret doors, magic mouths, teleport doors, and more. Today, B1 is thus a great example of of the tropes of very early D&D dungeon design, but polished and detailed much better than the typical dungeons of the '70s.
The adventure features one other element of historical note: The rooms don't actually list what monsters and treasures they contain. Instead, GMs were expected to fill in those details themselves from lists at the end of the book. This design decision may have been intended to keep players on their toes (as there was concern in those early days that players might read modules they were going to play), or it may have been another lesson in how to create a dungeon. Regardless, the decision wouldn't be repeated again, with the exception of the recalled adventure "B3: Palace of the Silver Princess" (1981).