Things that all games have common are
1. Rules: No matter what game you play, all of them have a certain set of rules and have to be followed by the player in order to play the game
2. Outcomes: Each game has a certain outcome, so if you play a game there is a definite outcome of an action
3. Players: Minimum of one player to multiplayer are allowed in each game
4. Properties: All games have some sort of properties