Extremely fun to play! I highly recommend this for experienced and novice player alike. "AD&D Silver Anniversary, Return to the Keep on the Borderlands Adventure", is a particularly well done rewrite of the classic original. The keep itself is described in plentiful detail, including numerous NPC descriptions. The area immediately surrounding the Keep is also well described with more than enough potential encounters to keep your players busy for quite some time. And the description of the Caves of Chaos, just a hop from the Keep, is very well written and an enjoyable read. This adventure module is certain to provide many sessions of fun and challenging play, and is definitely worth the money.
There are a few problems, however, which is why this only gets a 4 star review. First, the artwork dispersed amongst the text is pathetic. But that's a minor issue. More importantly, there are several inconsistencies that old Greyhawkers will surely notice. For instance, the location is not quite right, and the background for a few NPCs strongly conflicts with Greyhawk history. Additionally, a few of the potential encounters could easily wipe out a low level party, leaving all characters dead, or severely injured (missing limbs, etc.). Fortunately for you and me, some individuals were kind enough to publish "fixes" for the Return to the Keep on the Borderlands. The article is in an on-line journal called the Oerth Journal. It is a Greyhawk journal where DMs (and players, I suppose) write articles about Greyhawk. In the most recent issue, someone modified the new Keep on the Borderlands to make it a bit more survivable for low level characters, and to fit with actual Greyhawk canon material. No, it does not contain the complete module, that would be illegal, only suggested re-writes for a few paragraphs, and a great suggestion for more appropriate placement of the Keep in the World of Greyhawk.
The URL for the site is: http://members.xoom.com/cogh/ This is the Council of Greyhawk website. The Oerth Journal that has this article is OJ#11
With the corrections in this article this module would easily receive a 5 star rating, with out hesitation. As I stated, I strongly recommend you purchase this most excellent Adventure Module, sure to be enjoyable for months. And stop by the above mentioned web site to obtain the few fixes that will make this module truly outstanding!
Enjoy the Chaos!