| Series | Created by | Games | Genre |
|---|---|---|---|
| X-COM | 2K Marin, Mythos Games, Hasbro Interactive, MicroProse, Irrational Games, Firaxis Games | 9 | strategy video game |
| Xeno | Monolith Soft Inc. | 2 | action role-playing game, role-playing video game |
| Xenosaga | Monolith Soft Inc. | 6 | role-playing video game |
| Xuan-Yuan Sword | Softstar Entertainment | 12 | historical fantasy, role-playing video game |
| プロサッカークラブをつくろう! | — | 1 | association football video game |