2021 · ソースブック（プレイを拡張するルール／オプション）
Into the Wild
A rules supplement for Old School Essentials and other OSR-style games, focused on high-level play and wilderness adventures. It covers hexcrawling, random weather, wilderness lairs and encounters, domain building, settlements and strongholds, NPC wealth, and creating expanded character classes. The book also includes a simple mass-combat system for resolving large battles and wilderness engagements, unit tokens for use on 1-inch battlemats, example settlements and strongholds, and domain-tracking sheets. The rules combine and revise material from several related supplements, with examples of play.
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）クラス制（パイロット、ウィザード、サイエンティストなど）
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。