Comment by resonious
2 years ago
~15 years ago I played an MMO that was very real-time, and yet all of the communication was TCP. Literally you'd click a button, and you would not even see your action play out until a response packet came back.
All of the kids playing this game (me included) eventually figured out you could turn on TCP_NODELAY to make the game buttery smooth - especially for those in California close to the game servers.
Not sure if you're talking about WoW, but around that time ago an update to the game did exactly this change (and possibly more).
An interesting side-effect of this was that before the change if something stalled the TCP stream, the game would hang for a while then very quickly replay all the missed incoming events (which was very often you being killed). After the change you'd instead just be disconnected.
I think I have a very vague memory of the "hang, hang, hang, SURPRISE! You're dead" thing happening in Diablo II but it's been so long I wouldn't bet on having remembered correctly.