The ultimate sign of the divorce between the D&D and AD&D systems was this Expert Set released at the same time as the revamped version of the Basic Set. No longer were players supposed to graduate from the Basic D&D to AD&D, now they were supposed to continue with the expert set which covered players from level 4 to 14. 

The set bundled together this Rule book, a catalogue for TSR’s 1981 products and the first adventure designed specifically for the Expert level players, X1: The Isle of Dread. We previously had adventures for the Basic series with B1: In Search of the Unknown and B2: The Keep on the Borderlands, but no adventure for characters over level 3 in the D&D system, so that’s where X1 comes in. We’ll cover it in the next post. 

As was to be expected this volume of the rules gives details of changes to characters in the 10 levels that it covers, but it also gives us a list of level appropriate monsters, loot, magical items and spells that were not present in the Basic Rules. Another longlasting first in this rule set is the first inkling of the world of Mystara, the sample dungeon at the end of the rules being set in that world with the X1 module bundled also being set in Mystara. This was because Gygax wanted to make Greyhawk exclusive to AD&D, so D&D adopted Lawrence Schick and Tom Moldvay’s home campaign setting, a setting which would be the default for D&D over the 80s and into the 90s.