Adventure Construction Set (ACS), published by Electronic Arts starting in 1984, was one of the first RPG creation tools. It was written by Stuart Smith and patterned after his earlier RPG's Alibaba and the Fourty Thieves and Return of Heracles. ACS was eventually released for the Apple II, C64, Amiga and PC, but unfortunetly never got ported to the Atari. A while back I started to play with the MSDOS version and though it would be an interesting project to reverse engineer the file format. This turned out to be a lot harder then I expected but the results can be found on this page.

Wikipedia article
Moby Games
CRPG Addict Review

Here are some games that were created for the C64 version of ACS.

Hunting Dracula by Daniel Elmaleh
The Hobbit by Neil Tiedeman
The Journey by HPL, JT, and others
Magic by Michael Shapiro
The One Way Ticket by Robert U. Robot, ES
Pirate Treasure by Neil Tiedeman
The Ruby of Tomar by Dan Howlett
The Visitation by Jason Albert

Adventure Construction Set File Format (Draft)
Original Adventure Construction Set Manual

ACS Viewer is a tool written in C# that allows you to view the game data from ACS files in Apple II, PC, C64 and Amiga formats. Although I haven't figured out what every byte of the file format does, the view does work with all the out of the box games and all known user created games. ACS Viewer also provides a rudimentary play feature that allows you to walk around the map. I would like to expand this into a full player some day.

Thanks to James Read to made numerous improvements in the 2.0 version. Here are some of the highlights. See the release notes file for a full list.

• Support for Amiga and Apple II files
• Store contents are now accurate
• Palette colors and names now accessible from graphics viewer
• Can view players saved with the game
• A number of improvements to the Room Viewer
• All graphics are now shown in the graphics viewer

Windows Installer
Source Code on Github