Packed with tons of great info and a wonderful source if you're already steeped in BX or the OSR rules. Tons of monsters and rules for all kinds of encounters. A lots of great random tables too.

However, it's general layout is pretty weak and unfriendly and it spends a good page explaining what an RPG is and how to play one but never breaks down how Descending Armor Class works. So, it pretends to cater to new players and then kind of forgets about them.