Clash of Kings for Android is a real time strategy game with a typical medieval fantasy theme. There's a strong focus on base building, resource harvesting and troop training, with essentially no fighting action. Even your base development is rigidly defined, because there are so many rules about which buildings you need to have and upgrade before you can do other buildings.

You need to spend a reasonable amount of time upgrading your castle and surrounding fortress, and some farms and sawmills outside the castle walls. In app purchases are available in this game, but you certainly don't need them. Gold seems plentiful enough, and it's a single currency for all manner of speed ups. You also get wood and grain from farms and sawmills, but if you build a few of them and keep harvesting, neither of these will be in short supply. When buildings are nearly finished upgrading, you can finish the upgrade for free by tapping them.

There's a 'quest' element which actually means occasionally looking in 'quest' and collecting rewards for several achievements you will get just playing the game anyway. Then you can go out into the map and attack other nearby castles. Your troops slowly ride across the map, towards the castle, reach it and... that's it, the castle catches fire, you win or lose, and your remaining guys ride back again. There are also some centaurs you can attack in the same fashion.

You can join an alliance with other online players, and you can see their castles on the map. The map extends for hundreds of game kilometers in every direction, but it's all very samey, so that it's hard to really get an idea what your strategy as a team should be, or even where all your allies are in the big scheme of things. I'm sure Clash of Kings can get very addictive, but its a game that rewards a large investment of time and attention, rather than judicious strategy.