The key code for the "Star Wars: Empire at War" expansion pack is obtained by purchasing the expansion pack for the game. If the expansion pack is purchased as a download, the key code is emailed or appears after purchase. With a disc, the code is on the packaging.
Each key code, or product key, is unique to the gaming software purchased, allowing manufacturers to ensure the authenticity of each product. The key code is typically alphanumeric and must be entered to successfully install or activate the expansion pack. Gamers who misplace their key codes may be able to retrieve them by contacting the manufacturer.