Multiplayer games are formed as mesh networks, each player is connected to everyone else. Increases total upstream needs of all players but does not fall over if the "host" disconnects.
The first video game about Mesh network was released on September 14, 2006.
* Dedicated server
* Disconnect of any single player, including the host that set-up the original game, does not interrupt the game itself.
* Latency (ping) is effectively the same for all, the worst any of the players have.
* All players included send as much data as a traditional server would.
* Synchronization may be difficult, but this is only an issue for the developers.
* Game saves with exact position data are commonly impossible without delegating and trusting single peer in the mesh network.
* Spectators are expensive. Likely done via one of the players proxying the game for all spectators much like regular server would if done at all.
* Everyone or most need to have their firewall/NAT configured properly. Theoretically one and no more can have this improperly. Unless the net code implements routing via the other players.
Use of mesh network can be easily tested by setting up a game and the host disconnecting and shutting down their game/server, though in some cases this is inadequate measure. Forcibly killing the game process is most reliable way to determine this as it prevents on-the-fly server migration if the game is capable of it.