Command & Conquer: Red Alert 2 Cheats

Get one of your units to force fire on any building which can be spied so that it is slightly damaged, then stop your unit. Once the building is damaged, you will need an engineer and a spy. Select your engineer and then enter waypoint mode and click on the damaged building. Then select the spy, and you will see a waypoint line from your engineer to the building. Click on the square box above the building and you will see a waypoint line from your spy to the building. Exit waypoint mode and both of your units will enter the building. Now you have the benefits of having spied your chosen building, without the trouble of getting into an enemy base!

Note: this cheat may not work in all versions of this game.