Priests are special units that are trained at the Temple and are able to heal friendly units and convert enemy ones, but are slow-moving and possess low HP. A Priest cannot attack, but when an enemy units closes in to the Priest, he attempts to convert them. When there are wounded units of the player's side nearby, the Priest automatically heals them. Priests are able to heal all infantry, cavalry, and siege units, but not ships or buildings (the latter two require Villagers to repair). After a successful conversion, the enemy unit will switch colors to the team whose Priest converted him and be under control by its player. After a conversion, a Priest may not again attempt to convert until his rejuvenation meter has regained back to its fullest, at 100%.
If a unit attacks an enemy unit near an Elephant within range of an enemy priest, there is a glitch that may occasionally occur in which a priest will attempt to convert the elephant instead of the attacking unit. The conversion will always be unsuccessful and the priest may perish to the attacking player's advantage. This glitch only applies if the enemy is controlled by the computer.
There is a cheat code that grants Priests 600 HP and absurdly fast movement by typing HOYOHOYO into the chat box. Note that these statistics can be further improved to 1200 HP and even greater speed by activating the cheat code prior to researching Mysticism and Polytheism.
The acceptance of gods and goddesses associated with complex religions required the provision of priests (and priestesses) who acted as representatives of the gods among the people. Priests developed and conducted rituals, interpreted the demands of gods, taught and enforced the religious laws, and sought new believers. Particularly effective priests, or those representing a potent religion, were thought capable of healing.