For the first part, I think what you mean is "factions", and you are talking about Unique Buildings. Since there are so few civs, I think that this might be a good idea, it would make picking a civilization a task you'd have to think about and consider for their various bonuses, and it would increase the replay value a lot. About the things such as ambush - I think that these would be good ideas as specialized abilities for certain civs. For instance, could you see the Romans ambushing anybody? It'd be a good bonus for the Celts, especially when the Romans and Hellenes will probably be OP (just an educated guess, I know absolutely nothing about the actual game). Guerilla attacks sound good for raiding early in the game to weaken enemies early on, however this would probably be OP with cavalry, it would mean they do tons of damage and make the enemy spend all their money on troops to try and defend themselves. I thought about what you said and this is my idea. These things would be researchable Unique Techs that make certain abilities available, most of them tactical formations: Celts get Ambush. Historical reasoning is that since the celts usually knew their terrain very well and knew how to move silently they could ambush their enemies easily. The actual bonus would be to make the troops invisible until they start to attack, at which point they become visible. If this is too OP, it might be a good idea to make it only able to happen in forested areas. The Carthaginians would get Natural Harbour (referring to the natural harbour in Carthage). Their ships are build and repaired faster. The Hellenes would get Soldiers of Sparta, making all their units faster and stronger. If this is too OP, maybe just limiting it to infantry would be best. Iberians get the Raiding Party ability. This would be something akin to the Patrol or Guard abilities in AoE. You simply select the raiders, click Raid, and then select the area they are raiding. They will go to the area and fight any enemies in their area, however, they will target non-military units as well as trying to raze buildings. After 15 seconds, they retreat back to where they were before they started the raid. Persians get Massed Infantry, that allow their infantry to be created in batches of 5 and to also be created faster. Finally, the Romans get Roman Discipline. This battle formation means that a certain block of infantry stick together in a block despite what is around (except for terrain). That way, your legionaries won't immediately run around and bump into each other trying to get at the enemy soldiers, they'll stay in an orderly formation and only fight or the soldier in front of them dies. Some of these might be hard to implement, especially the Roman Discipline one, but most commercial games go for eyecandy and graphics instead of solid gameplay values such as formations. I've always been a fan of RTS being more tactical and less strategic, so instead of just having a game where you throw your mob of troops at the enemy mob of troops and hope that you can overwhelm them with superior numbers or better upgrades gets boring very fast.