Ah... This was my first Dungeon Master's Guide back in the day before there was an official Dungeon Master's Guide. Tons of useful charts, generators and inspiration in this little treasure. If you're playing OD&D or Basic D&D (Holmes or Moldvay) you should be able to drop this material right into your game with no problems. This is about as Old School as you can get but definitely worth the price as it contains most of the generators and information that was gleaned from other Judges Guild products...
[5 of 5 Stars!]