Approach A: one typed condition/effect vocabulary (GameState + Conditions + Effects) reused by five integration points (locked exits, state-dependent descriptions, conditional NPC dialogue, reactions with requires/effects, switch effects). All new YAML fields optional. Light/dark, item-combination, quest objects, endings deferred. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>