Cook/Marsh Expert

The first edition of the D&D Expert Set (for character levels 4-14) was released in 1981, alongside the revised D&D Basic Set.  Higher level play was to be covered in the D&D Companion Set (for character levels 15-36).

D&D Expert Set (1981).  Cover illustration by Erol Otus, from a design concept by Jeff Dee.  (For earlier cover art proposals by Jim Roslof, see here and here).

The set included a 64-page rulebook, dungeon module X1 "The Isle of Dread", a set of polyhedral dice (together with a crayon to fill in the numbers), and the "Gateway to Adventure" TSR catalog.

The rulebook was edited by David Cook with Steve Marsh.*  Cook was hired by TSR in 1979, and also co-wrote module X1 with Tom Moldvay (see Grogtalk Episode 59, June 10, 2020 and Shane Plays Episode 243, July 1, 2021 for recent interviews).

*Marsh prepared the initial typewritten manuscript of the D&D Expert rulebook during his 1980 summer break from law school (see Grogtalk Episode 80, April 13, 2021 for a recent interview)

D&D Expert Rulebook (1981).  First printing (no white circle around the 2 in the upper left hand corner).

The title page credits both Gary Gygax and Dave Arneson.  Copyright is listed as 1974 (OD&D), 1977 (Holmes), 1978 (revised Holmes with material from the 1e Monster Manual), and 1981.*

*early printings only credit Dave Cook, and copyright was listed as 1980 (see here)

Illustrations were by Jeff Dee, Wade Hampton, David S. LaForce (Diesel), Erol Otus, James Roslof, and Bill Willingham.

The expanded scope of the rules involves adventures in the wilderness and establishing domains:

Adventures will take place outside the dungeon.  A "wilderness" area will be an even greater challenge to players, with stronger monsters and greater wealth to be won.  In expanding the campaign, the DM will create whole nations and cultures, giving the characters a history and background.  Adventurers can even shape the history of their world as they become more powerful.

As player characters grow in wealth and power, they may build castles or strongholds to keep themselves and their retainers safe.  They may encourage settlements around their fortresses in order to support them, eventually becoming rulers of their own territories.  From their wilderness bases, they can settle and rule larger areas, bringing civilization to the wilderness.

D&D Expert rulebook (1981), pg X3

Advice is also given for using the D&D Expert rules with Holmes Basic, for a Holmes/Cook/Marsh or Holmes/X campaign, summarizing the changes introduced by Moldvay Basic.