The Genie Engine is a game engine developed by Ensemble Studios and used in several popular computer games, such as Age of Empires, Age of Empires II and its expansion (but is not used in other Ensemble Studios games) and Star Wars: Galactic Battlegrounds. Some of those games have been ported to the Apple Mac.
The Genie Engine has several features that are common across all its games, including a scenario editor, campaigns, LAN, serial and TCP/IP multiplayer, background music amongst others. The engine uses an isometric tile set, unlike other real-time strategy engines such as the one used for Warcraft.
In general, the engine is easy to use. Units can be highlighted by dragging a box around them, or . tells a unit to attack another enemy unit or building. Groups of units are remarkably well-disciplined in that they adhere far more rigidly to formations in movement and while stationary than units in other game engines.
The computer's A.I. is usually made up of sending "skirmish" type attacks. These usually are characterized by constantly sending a small (but also easily overwhelmed) number of units (usually 1 or two) that attack from range then run away before being attacked. Computer AI will also do this with melee units, with far less effectiveness, as the melee units must come much closer to opposing forces before being able to do damage and withdraw. While innovative it is nearly impossible for a human to effectively counter with non-ranged (also non-siege explained later) units (unless interceptor units are assembled in advance, as they typically will be after a few of these attacks) due to micromanagement issues. It is also almost useless in that it does little more than annoy (albeit continuously) a human player.
Enemy A.I. is extremely effective (whatever the problems of individual unit AI) at negating AOE (area of effect) siege units. When fired upon the A.I. will instantly move to a safe location, effectively nullifying the effectiveness of nearly 1/3 of the available units in the game. A single computer controlled cavalry archer is capable of dodging 40 cannons or catapults for an extensive period of time. However, it is also common to see computer units move into the line of fire of active AOE units.
The game lacks an "attack through" command. An attack through command orders the selected unit(s) to move to a selected area attacking all units along the way. Instead on games based on the Genie platform, the player must tell the selected unit(s) to stop, then to attack individual units. This frequently causes a mis-click causing all units to stop attacking and move to an unneeded area. It severely reduces the effectiveness of melee units, most notably slower moving infantry. This can be somewhat levied by using patrol command, which sends unit back and forth, while attacking units along the way.