There's not a whole lot of information yet about multiplayer, and Age of Empires III players are no doubt expecting an improved experience that revives the competitive scene. You'll be able to learn the game's meta, getting you up to speed in no time. For newcomers and for anyone who needs to brush up on their fundamentals, Art of War is also making a return following its popularity in Age of Empires II: Definitive Edition. Historical Battles are self explanatory, covering important skirmishes that occurred during the Age of Empires III time period.
Two new game modes are coming to Age of Empires III: Definitive Edition.