Switching from wifi to a wired connection sovled this for me. If someone else is using wifi it might cause problems too.

Have the host set V-Sync on in the options.
Fixes desync.
If the host is up for it what we did was use a different seed to place all the trophies eliminating 98% of the swarm of attacks on a local world map.. Could make the game bit boring for you though.
I've also heard Iron Gate maybe consdering upgrading the game engine which I hope is true and should fix a lot these issues.

maybe that [forum.g-portal.com] helps

Things start to rubberband opening doors and chests takes a couple of seconds to work enemies fly around and hit you even tho you dont see them etc...

Originally posted by Iranian_Dude:

The desync problem is kinda annoying when its just me and my 1 friend its fine but as soon as a second person joins it becomes unplayable previously i stopped playing because after killing the elder the desync started and it caused me and my friend to quit but recently we came back and it seems that again after killing the elder the problems back and one find a solution or any tricks to help with it?

The person with the worst network throughput is usually the one who is causing desync. The game is sending huge data packets, and expects all to be received in time. If someone fails to do so - everyone will feel desync. Ask the person to get a better network/find a way to host the server somewhere both you, and the person have a good ping to. Host a server that is physically and geographically inbetween you and the person.
Another way is to spend more time apart. The desync is usually nonexistant if you spend more time at different parts of the map.

Originally posted by DarkSlayerofDarkness:

New to this. How does the problem manifest?

At first it looks like you're getting delays between your actions and the server's reactions to them(2-3 seconds delay between interacting with a chest and actually getting it opened).
Then, as desync grows, you start seeing other players run into walls, npcs float, fall through ground, teleport. All that until you have no more control over the game.
In best case - the desync will hold at certain level. In wost case - everyone will have to rejoin to stop the issue(for half an hour. Then, the issue will start all over again).

"The person with the worst network throughput is usually the one who is causing desync. The game is sending huge data packets and expects all to be received in time."

This has been driving us nuts, we are giving up on the game as it has gotten worse since the last update. If we are in the same map area, we just can't play together which is the point of "playing together" :-)

I read the developers notes about how multiplayer works and it appears that the server doesn't do the mechanics, but the client does. Therefore, when you are by yourself on a map everything happens instantaneously but as soon as a friend gets near doors go wonky, monsters hop around the screen, or you do no damage or take ghost damage. The reason it goes wonky is that you or your friend are processing the game mechanics and then relaying the output via the server to each other. It is a whack way of doing it, great when you are by yourself as the game is lag-less but when playing with friends it is a nightmare.

The game is designed to be multiplayer but not to play together.

New to this. How does the problem manifest?