“Act now, apologize later”

Fighting games require rather precise timing: the action is frenetic, the inputs rapid, and the outcomes can be determined by what players do down to – sometimes – individual one-sixtieth-of-a-second frames. This is fine when you play locally, but gets infinitely more tricky the moment you attempt to kick someone’s more remote ass: Information sent to your opponent may be delayed, arrive out of order, or become lost entirely depending on dozens of factors, including the physical distance to your opponent, if you’re on a WiFi connection, and whether your roommate is watching Netflix. The part of the game responsible for dealing with networking is called netcode, and the classic solution to the lag problem has been delay-based netcode with a sort of lowest common denominator approach: if your opponent has a “ping” of 50ms, your actions will also be delayed by 50ms, to ensure fairness. It’s not that hard to imagine many problems with this idea. Lag comes and goes but the game doesn’t…