Book excerpt: GUIDELINES FOR PLAYING CALL OF CTHULHU IN SEVEN DIFFERENT ERAS CTHULHU THROUGH THE AGES was created to help players adopt the latest rule-set for the wide range of settings published by Chaosium Inc. Here you will find straight-forward guidance and era-specific rules for investigator creation for seven different settings, along with updated rules for combat for CTHULHU DARK AGES, CTHULHU INVICTUS, and MYTHIS ICELAND, as well as a sprinkling of other topics like scenario seeds, setting-specific monsters, and investigator organizations.