2005 · 资料书（用于增强玩法的规则/选项）
Changing the Rules
A 13-page PDF supplement for the d20 System that introduces rule changes addressing several disparities in the core rules. It focuses on environmental dangers, hit points, and combat, providing guidance for incorporating a greater degree of realism into campaigns.
技能型（购买或获得技能）基于属性/数值（STR、CON、PER 等）等级制（获得经验值并升级）
免费，支持网页、Android 和 iOS
用 Ludoya 玩 Changing the Rules
游戏信息（人数、游戏时长、年龄、制作人员）来自 BoardGameGeek。