2013 · ソースブック（プレイを拡張するルール／オプション）

Story Mechanics: Incremental Antimagic

This supplement introduces a concentration-based system for areas, creatures, and effects that interfere with magic. It presents four forms of incremental antimagic: chaotic effects change a spell’s form, delaying effects postpone or redirect its casting, eliminating effects cause it to fizzle, and hindering effects require an additional spell slot or cancel the spell. Rules cover integrating these effects into a campaign and adjusting the challenge of affected monsters and encounters. The supplement also includes the nullstone golem, a CR 5 creature built around antimagic.