Modern games use Pixel Shaders to render beautiful water among other effects. AOE3 does this in the lakes, the oceans and the rivers. AOE3 is said to require Pixel Shader 2.0 to play. Shadows on the ground match the lighting of the sun, and the object they're shadowing. Microsoft says they have implemented High Dynamic Range Lighting in the game. Ensemble Studios licensed the Havok physics engine for the game. Barrels break realistically, ships get damaged while fighting, the buildings get progressively more damaged as the enemy attacks it etc.

The scale of the game is set for the RTS scene; after all, a first person view would cause the game to be totally unplayable. Sound in the game takes advantage Microsoft's DirectX sound API DirectSound. Each character in the game: Morgan Black, John Black, Kenyanke, Amelia Black et al has a distinct voice. Every civilization in the game has a unique "voice to it" as well. The Spanish troops speak Spanish; the Germans speak German when asked to perform a task. Explosions, gunfire are what you would expect out of a game. The music in the game is suitably militaristic for the time period represented in the game.