Manual of War

Wondrous item, rare (requires attunement)

Bound in bloodstained leather, this heavy tome is scarred like the flesh of a seasoned warrior and contains many generations of martial knowledge.

When you complete a long rest, you can study the manual of war for 1 hour, after which you can exchange one feat you possess for a different feat.

Both the feat you exchange and the feat you gain must be feats directly relating to combat, armor, and/or weapons. The exchange persists for 24 hours or until you complete a long rest; however, if you wish you can study the tome again for 10 minutes to end the exchange and regain your original feat.