HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

What do social networks have to do with it? It's simple: the first thing you want to do when you enter the lobby is to see who among your acquaintances is online and who they are playing with. When there are 700 people online in the lobby, it becomes quite problematic to do this. How can this be implemented? Introduce "regular opponents," "friends," or whatever you want to call it; this is a necessary feature. You want to find an opponent among your acquaintances. How do you do that? Do you scroll through 700 people, look for acquaintances, and write to each one? That's not very convenient. A "friends chat" would even be useful for the developers to discuss solutions to current tasks in a private chat. Saving personal messages is also often required in practice – an opponent sends you a password, you look at the saves, close the game, and then you want to look at the saves again. What do you do? Do you write to him again? You want to arrange a game with an opponent, but he rarely logs into the lobby. What do you do? Do you write to him on social networks or in ICQ? It is also often necessary to write to friends when they are offline. All of this is not just "nice extras" – these are things that are necessary in practice.