FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
THE ECONOMY OF GOD GAMES
In a god game, the player's power, usually called mana, grows along with the number and prosperity of his worshippers. The size of the population typically influences two critical values: the maximum amount of mana the player may have and the rate at which mana is restored when it is below maximum. Using godly powers consumes mana, and the player spends much of his time using his godly powers for his people's benefit—flattening hills to make good farmland, reclaiming land from the sea, blessing their crops, and so on. Mana often grows in exponential proportion to population size, so as the population increases the player acquires vastly greater powers—a progression that god games share with spellcaster characters in role-playing games. However, if his population declines, the maximum amount of mana that he may expend declines also, reducing his ability to help them.
The close connection between population size and available mana can easily create runaway positive feedback: The more mana the player gets, the more he can do for his people, and the more their population grows, the more mana he gets. Positive feedback is usually limited by several factors, however. First, his people do not reproduce instantaneously, so in spite of the player's increasing power, he cannot force rapid population growth. Furthermore, they often need land in which to expand, and creating suitable land consumes mana. Second, the mana cost of using his higher-level powers also increases exponentially, so mana growth is balanced by increased spending as he exercises his powers. Finally, many of his higher powers cannot be used to help his own population, but only to do damage to his rival's people. The next section addresses this issue.
