The version of the old D&D setting and by many considered the best. A partial compilation of all the BECMI sets with many new rules and the skill system taken from the gazetteers. For only $25 it's a complete game, with treasures, traps, monsters and a character generation system to take you from levels 1 to 36. Even if you don't play the rules, the domain management and mass combat systems are fairly rules neutral and can be stolen across any version of the rules.