To succeed, you need to balance the money, public order, corruption levels and other resources - all while efficiently building up infrastructure, recruiting units, moving armies around and researching technology. While the battle mode relies on your tactical thinking and ability to maneuver and field armies, the campaign is a strategic challenge.If you don't want to play a battle, you can autoresolve it instead. When two enemy armies meet (or when an army attacks a settlement), there will be a battle. You can also engage in diplomacy and trade, or wage war. You need to construct buildings, recruit units, manage money and other resources, as well as moving armies around the map.
The gameplay for most factions (except hordes) revolves around controlling settlements. In provinces are settlements and various types of terrain. The campaign map is divided up into provinces.
Then all the other factions each get a turn, and then it is your turn again. The campaign is turn based, you perform all the moves you want and then end your turn. Each race (and sometimes even individual factions) has it's own unique gameplay mechanics, units, buildings, and more. You can also adjust the overall difficulty slider. Each faction has a different starting position and starting difficulty.