With an option of 13 civilizations to choose from, the Age of Empires combines world building skills that utilize military, economic & crafting aspect. You have to manage manpower, including military & civilians & put them into effective use to flesh out your kingdom & dominate the rival civilization.
Each civilization comes with perks & unique advantages. From upgrading buildings & weapons, armor to soldiers, you go from each new age into other with more options of upgradation & scalability.
You can play against computer or other players as well which makes this so much fun, with loads of replay value as you constantly keep on learning. Each game lasts long & has tremendous satisfaction value as you build walls, forts, man outposts, build wood, gold & iron supply effectively while farming to make sure you have the right resources in plenty to conquer your enemy. You can also send & receive tributes from allies. The level of detail & customization is very high, as is the steep learning curve.
You'll soon learn of the computer's propensity to use guerilla tactics and fall prey to particular tricks. You can start with a ton of resources and just have at it in the deathmatch mode; you can set out to kill the enemy king in a regicide match; and you can play one of Age of Kings' five historical campaigns. These campaigns focus on such legendary leaders as Joan of Arc, Frederick Barbarossa, and Genghis Khan in a series of linked missions.
This is one of the best RTS games of all time.