Age of Empires is one of the most well-known RTS franchises, and Microsoft surprised fans in 2017 by announcing the return of the franchise, helmed by Relic Entertainment. Age of Empires 4 will be the first new game from the franchise in 15 years, and it's hard to state how much the RTS genre has changed in that time.
Those 15 years have seen the release of games that brought wildly new ideas to the genre, like Starcraft 2, Company of Heroes, Total War, Halo Wars, and Sins of a Solar Empire. Age of Empires is still a beloved series, but the face of the genre has changed.
With that in mind, Age of Empires 4 will need to make some serious changes to the franchise's formula if it wants to succeed. There are core tenets that make Age of Empires what it is, but there are several innovations that Relic can bring.
Age of Empires 4 Needs More Robust Diplomacy Options
Diplomacy has always been a factor in Age of Empires, but it feels a bit limited compared to other titles. In general, diplomacy simply lets players ally with others and trade resources, and Age of Empire 3 simplified those systems even more. Modern RTS titles generally allow for robust diplomacy options, especially 4X games like Civilization and Total War. Age of Empires 4 doesn't need to go that deep, but diplomacy can be used more interestingly during matches. Players should be able to receive more dynamic bonuses by using diplomacy, and not just extra income. Some kind of research tree for diplomatic relations would make matches more dynamic, especially if Age of Empires 4 puts things on a larger scale than before. The game could also have an alternate multiplayer mode where players can change diplomatic relations multiple teams and join different teams. As an alternate mode, it'd be incredibly chaotic, but it could work. Along those lines, it'd also be interesting to see a mode that makes everything entirely focused on economy and diplomacy, not requiring combat to win.
A Full-Fledged Campaign With a Focused Story
If there's one thing that modern RTS games have gotten right it's engaging campaigns. Titles like StarCraft 2 and Company of Heroes offer robust campaigns, detailed stories, and varied mission design. The first two Age of Empires had a bunch of micro-campaigns for each civilization, and while the mission design was decently varied the stories left a lot to be desired. Age of Empires 3, on the other hand, tried to tell a more focused story.
Age of Empires 4 can improve upon that even more by focusing on a central cast of characters, and having progression that reaches across the entire campaign. This could take the form of a home base that changes and evolves, like in StarCraft or XCOM, adding more bonuses and options as the player progresses. In terms of mission design, the best thing Relic could do is look at the series' past, and Age of Mythology in particular. The campaign in Age of Mythology did a fantastic job of keeping missions diverse, from one mission where a tug-of-war ensues with a piece of Osiris to one where players transform a limited pool of soldiers into myth units. A grand campaign, on top of strong core gameplay, could really make Age of Empires 4 something special.
Wildly Different Civilizations
Age of Empires 2 is widely regarded as the best game of the series, but if it has one flaw it's simply too many playable civilizations. While each civilization in Age of Empires is different, by today's standards they aren't different enough. Each civ has unique research and units, but other than that they all play the same in terms of basic units, gathering resources, building, etc. Again this is where Age of Mythology shined, as even though it only had three civilizations, they each played completely different. Age of Empires needs to ensure that its civilizations don't simply feel like carbon copies of each other, and each one plays integrally different right down to the basics. One way to do this is to focus on a smaller group of diverse civilizations, so maybe six in total rather than sixteen. Of course, the benefit of modern development is that future civilizations can be rolled out in regular updates.
More Detailed Environments and Weather
If there's one thing that's changed the most in the fifteen years since Age of Empires 3, it's development technology. Developers can create astronomically more detailed worlds, and that can play into the map design of Age of Empires 4. Elevation and geography have always played a factor, but for the first time, Age of Empires 4 can make terrain really matter. Maybe units move slower through sand and mud, or cavalry becomes less useful on certain types of terrain. A dynamic weather system could also throw things for a loop, by forcing players to adjust their strategy based on rain or snow. As a historical RTS, adding even more realism into Age of Empires 4 certainly wouldn't be a bad thing.
Age of Empires 4 is currently in development for PC.