Restriction: The monk eats nothing but rice (or a similar bland, staple food) and drinks nothing but water. On certain days (usually once per month or on a religious holiday), he may eat a small portion of other simple, bland food to maintain proper nutrition. The monk cannot use tobacco, drugs, potions, alchemical items requiring eating or drinking, or any other thing that could be considered a food or beverage.

Benefit: A monk with this vow increases his ki pool by 1 ki point for every 6 monk levels (minimum +1).