Similar to other fantasy turn-based strategy games, namely
Heroes of Might and Magic I-III,
Disciples II: Dark Prophecy includes three main game play elements: city management, resource management, and combat. Unlike those games, it rarely gets bogged down in the details, and also adds a fourth element, diplomacy.
Since one aspect of city management, building structures, is a fairly small part of the game, once they have all been completed, it is necessary to create a suitable army to defend each city. From then on, cities are mostly used to either create new heroes, recruit new troops, heal and resurrect troops and heroes, or research and cast spells. In addition, cities can transform surrounding land, which makes it easier to acquire resources.
Resources generate cash or mana. Cash is used to hire troops and build structures, and mana is used to research and cast spells. In order to acquire resources, the land surrounding the resource must be of the same type as the people who wish to take ownership of them. This can be accomplished either by possessing cities near the resources, or by planting rods near them. A special type of hero can plant or remove rods, which means it is possible for one side to plant a rod, and for the other to remove it.
But even resources do not make up a large part of the game. What does is combat, and Disciples II: Dark Prophecy offers rewarding turn-based combat. When enemy armies, which are each made of a hero and up to five units, come in contact, they clash. The view changes to a close up, and each side takes a turn based on initiative. It is simply a matter of clicking on an enemy hero or unit to attack it, and after doing so, combat is resolved through an animated sequence. If a hero is equipped with a spell, they can cast it during their turn.
As heroes and units win skirmishes, they gain experience points (XP), and they occasionally level. If required structures exist in your cities, units can progress in rank when they gain enough XP. When heroes level, they can increase their statistics, as well as gain special abilities.
Diplomacy seems to be a small part of the game, and doesn't come into play in all of the sagas (which are campaigns made up of multiple quests) or quests that come with the game. The interface for diplomacy, though allows you to sell items and forge alliances.