From the MMP Website:
ASL Journal 13 is a 52-page magazine for Advanced Squad Leader and features articles, the latest errata and scenario updates in the Debriefing, 33 new scenarios printed on cardstock (including four “pocket” scenarios, with the map board included on the card), ASL board 77, and overlay X20 (to replace the version that came in the ASL Overlay Bundle).

ASL Journal 13 articles include:

Hatten In Flames: CG I Impressions wherein Gary Bartlett & Mike McGrath discuss approaches both German and American players might take in tackling this Campaign Game.
In (Not So) Free Parking, Phil Palmer uncovers some facts about Hull Down positions and how valuable they may actually be to your AFV.
Advanced Nuggets 2 finds Paul Sidhu & Rich Spilky illuminating even more obscure and easily overlooked rules.
Radio Contact Essentials offers a primer by Rich Spilky on the basics of this critical element of ASL OBA.
Second Impressions finds Rich Spilky musing on OBA draw pile probabilities in this extension of Robert Medrow's essential article in THE GENERAL (and ASL CLASSIC) on OBA in ASL and providing a basis for the “Pleva variant” for OBA chit draws.
Alternative OBA Systems by Jim Bishop explores additional chit replacement methods in this follow-up to Rich's draw pile article.
Ken Dunn gives us a Preview of the Drop Zone: Sainte-Mére-Èglise Historical ASL module.
Forgotten War Designer's Notes author Kenneth P. Katz was a key contributor to the creation and evolution of transitioning ASL to the Korean War, and herein offers insight into that process.
A Tale of Two Scenarios is John Slotwinski’s analysis of the original and updated versions of the YANKS scenario The Mad Minute, revered for its fun factor but notoriously unbalanced.
Per Mare Per Terram is Andrew H. Hershey's follow-up to Ghost Killers from ASL Journal 12 and covers the history of 41 (Independent) Commando of the Royal Marines in the Korean War.
The Debriefing offers this issue's errata updates.

ASL Journal 13 has 29 ASL scenarios and 4 "Pocket" Scenarios.: