Why the netcode issue exists, and why it cannot be fixed.

[Astarica]

Timestamp doesn't get around the fact that server doesn't have the data at the time it makes its decision. Let us imagine this sequence:

Time 0.0s - Client sends position, player is in AE.
Time 0.01s - Player moved out of AE.
Time 0.15s - AE fires on server.
Time 0.30s - Client sends position, player is out of AE.

The server at time 0.15 only knows about your position at 0.0s (and earlier). It has no way of knowing your position at 0.01s. That information, even timestamped, comes at the next update at 0.30s. Currently, the server doesn't wait for the next update and just decides based on your last known position, so you get hit.

So I guess the natural thing to ask is, can't the server wait for the next update? Sure, it can do that, which means its decision will be rendered 0.15s later (and in general it can be up to 0.3s later). Now I'm sure all of us have seen the case where a guy managed to run really far after the castbar ended and then get hit half a screen away. Now you'd have even bigger delay if you indeed did not get out of the AE (because the server has to wait longer). While this method would yield the correct result, I'm not sure if you can add more lag to this game and have an acceptable playing experience, even if it is the correct one. It's common to get hit by an AE about half a second after you see the castbar end. With this method it can be up to 0.8s. It'd simply be a very jarring experience to get hit by an AE that late, even if the result is correct. If you indeed dodged the AE, this method would always credit you for dodging it. But if it turned out you actually didn't dodge the AE, you can expect even worse lag between when the AE hits compared to now. I find the lag in this game is already very disruptive, and I think adding more lag, even if it benefits the player, is likely going to produce an unplayable product.