This issue of Adventurer's Club, #13, marks a return to the magazine's roots... it only includes content for Hero Games products. Iron Crown Enterprises had already made the decision to start it's own magazine ICE Quarterly (or IQ) to feature MERP, Rolemaster, and Space Master, when AC #12 was in production.
Production delays kept this issue off the shelves for some time, but when it finally arrived it was marketed as a double issue, and in fact the magazine is 112 pages long (40 pages longer than the typical issue from this period). As the editors put it... "The first half of the magazine is Issue 13, the special supernatural issue, as mentioned; and Issue 13 1/2, in the second half of the magazine, is a more general issue, its special feature being the 'Raid on Fort Knox' adventure for Champions."
The cover of Adventurers Club #13 says 1989, but the credit page lists 1988. Given the production delays, 1989 seems like a more realistic release date.
Cover by Ben Dunn.