How to get it
- Loot after beating the Jack of Rainbows (twice per run).
- Merchants have a chance to stock one; the Lucky perk and Rare Goods decree raise it.
- Gacha at max level, Diffract and the Refraction decree give random Rainbow cards.
Other Jack of Rainbows tomes
Data: 9 Kings 1.0 card table on the official wiki, imported 2026-11-13.