Sci-Fi games are based on actual or imaginary science, not magic, where today's Science Fiction could become tomorrow's reality.  Sci-Fi games feature technologies beyond those currently known to man, whether they are still to come in our own future, or belong to aliens from other planets.  Such technologies are often a normal part of the everyday lives of the characters in these games.  Sci-Fi games often include scientifically plausible phenomena, such as wormholes or time travel, as plot devices in their story lines.