The Water Margin
The scorching sun of Athas wicks away moisture in an instant. Most of the Tablelands are covered in parched deserts, badlands, and silt estuaries. Only in a few isolated places does water flow, and then irregularly or in small quantities hidden away in the lee shadow of a mountain or under a canopy of gnarled trees. In the city-states, deep wells supply water to the populace, but in the wild, sources of water are few and difficult to find.
To emphasize the scarcity and importance of water, players will be awarded small tokens to represent the water available to their characters. A blue token represents a quart of water, while a violet token represents a gallon of water. Players must find their own clever ways to increase their water supplies.
A typical humanoid requires one gallon of water per day. This amount is halved if the character spends the time mostly in shade or indoors, and is halved again if the character spends the majority of the day resting and avoiding strenuous exertion. Wearing a full suit of metal armor doubles the amount of water required.
Half-giants consume four times as much water as other humanoids, while thri-kreen subsist on a mere gallon per week.