The most reliable public source for a verified copy is the Internet Archive. Search for "I 2d6 Dungeon Revised - Alex Yari." Look for uploads from user "Solo_RPG_Archivist" or "Old_School_DM." These files have been scanned by the Archive’s virus protection and are viewable directly in your browser.
Nothing is worse than printing a booklet only to find that page 3 is a blurry screenshot and page 6 is missing the monster table. Verified PDFs are professionally formatted, text-searchable, and correctly paginated for booklet printing. i 2d6 dungeon pdf verified