The precise mechanism by which this aspect of religion operates differs from game to game. In "Zeus", the player constructs massive temples, known as sanctuaries, to honor the gods. The god whose sanctuary is constructed will then give great benefits onto the player's city so long as the sanctuary is staffed and given the necessary sacrifices of either food or animals. Depending on its size, a city in "Zeus" could support up to four sanctuaries, with the player being given a selection from the Greek pantheon. The player also has the option to pray for a god's unique assistance via their sanctuary, although sometimes the god will provide the service independently if there is a need for it. Conversely, unfriendly gods can invade a city, attacking walkers and cursing or destroying buildings. In some cases, an unfriendly god will unleash a monster within a city's territory.