The Gemini Effect is a special weapon of the game Star Trek: Armada. It is cast onto a specific ship and effectively clones it. The copy will remain for a while, actually dealing damage and receiving damage (can also be destroyed). The only difference between the clone and the original is, that the clone will have no special weapon energy, so it will not cast any special abilities. It is researched at the Science Station. The Gemini Effect in action looks like this:

This special weapon can only be cast onto friendly ships.

The Gemini Effect is also used by the campaign ship Premonition.