The games that come out these days almost always have prequels or sequels lined up. Apart from the mechanics and characters that may stay same, it is important that the players can link the prequel or the sequel of the game to the game they played before. This makes it all the more exciting to play the prequel or the sequel. For making such connections, an interconnected story-line serves a key-role in game design.
Examples[]
1. Mafia II[]
Mafia 1 Ending In Mafia 2
In Chapter 14 of the Mafia II game there is a killing cutscene where a a guy named Tommy Angelo is killed. He is the protagonist from the first Mafia who is murdered by the NPC in the second Mafia game. The murder is also shown as the ending for the first game.