2005 · ソースブック（プレイを拡張するルール／オプション）
SFX Skills: Diabolism
A toolkit for adding diabolism to modern or fantasy d20 role-playing games, drawing on occult horror traditions of demonic bargains, ritual sacrifice, and forbidden knowledge. It introduces a flexible SFX Skills system built around familiar feat and skill structures, with rules for controlling access, feats, and a Background for occult scholars. The system supports characters from 1st to 20th level and can be used in low- or high-magic settings. Guidance covers villainous NPCs, heroic characters, and using dark skills against their practitioners.
スキルベース（スキルを購入または獲得）属性／ステータス制（STR、CON、PERなど）レベル制（XPを獲得してレベルアップ）
ゲーム情報（人数、プレイ時間、対象年齢、クレジット）の出典：BoardGameGeek。