2022 · ソースブック（プレイを拡張するルール／オプション）
BX Game Options Volume IV
This supplement adds optional feats to an OSR fantasy campaign, with 86 choices ranging from agile fighting techniques to weapon mastery. Characters invest in feats as desired rather than receiving them automatically at set levels. It also introduces barbarian and shaman classes, including spirit-focused spells and rules for crafting totems and fetishes. Additional rules allow magic-using characters to create potions, scrolls, wands, and staves during downtime, provided they have the necessary time and funds, though the process may fail.
レベル制（XPを獲得してレベルアップ）クラス制（パイロット、ウィザード、サイエンティストなど）種族ベース（プレイヤーの種族/種がゲームプレイに影響する）
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。