Networking mode
General Overview
Path of Exile had a problem. Desync issues plagued the game, meaning players would be in one location in their game client, but the server placed them elsewhere. This led to lots of monsters killing players who thought they had moved to safety.
But thanks to a new piece of netcode desync is a thing of the past. The new “Lockstep” mode keeps everything on the client and server synchronised, and stops those unfair deaths.
With the expansion GGG are adding a Deterministic Lockstep mode to Path of Exile that will have no desync. Bear in mind that this means that when you click you will have to wait for whatever your ping time is before you start to move or do a skill. This works the same way as you would see in strategy game like Starcraft or a MOBA like Dota.
two options available to choose between
Deterministic Lockstep:
When you perform an action, it is sent to the server for confirmation before it is shown to you. In this mode everything will stay completely in sync, including all monsters. There is a delay equal to your latency to the server. If you suffer from an internet lag spike, everything stops moving until you receive more data. This mode is amazing if you have low latency to the server.
Client Predictive:
This is the mode we currently use. Actions appear to occur immediately but can get out of sync under some circumstances. While things appear to happen immediately, the actual actions are still delayed by your latency behind the scenes. Many bugs with this mode have been uncovered during the implementation of Deterministic Lockstep and have been fixed. It's much better than it was before, and is probably the best choice if you have more than 100ms of latency to the server.
Deterministic Lockstep represents a gigantic amount of time and re-engineering. Substantial testing is needed to make sure that everything functions properly once it's deployed.