Keeper's Compendium is a 1993 role-playing supplement for "Call of Cthulhu" published by Chaosium. Contents. "Keeper's Compendium" is a supplement in which forbidden knowledge is presented for the gamemaster. Reception. Wayne Ligon reviewed "Keeper's Compendium" in "White Wolf" #48 (Oct., 1994), rating it a 4 out of 5 and stated that "This is one of the best reference works a Keeper can have."