desync question

What does desync do to the game?

I've seen people talk about it before.

Creating/destroying objects for a single player (bad use of GetLocalPlayer) for example.

Desync is the term for when a multiplayer game desynchronizes; it's when you get a server split. A warcraft map isn't run on the server which would then send information to other players; instead, all computers run their triggers individually and then compare the state of the game; if it becomes different on different computers, you get a desync.

Most often, desync is caused with the inproper use of GetLocalPlayer(). This function returns the player on who's machine the trigger is running, so in a multiplayer game, it will give a different value for each player when called. If you use this value in a way that alters the state of the game (for example, creating or destroying game objects for only one player), the game desyncs.

There are other ways to desync a game, for example, extremely high damage or bounty dice values are reported to cause this as well.

Weird cause i used local player for quest logs and no desync.

Altering things for a local player that the game doesn't synchronise doesn't cause desync, obviously. There's a whole bunch of things you can do for one player that won't desync; only things that do are things that need to be synchronised, like handle objects (units, items... you can't destroy or create those for just one player).

GetLocalPlayer has many uses - making buildings transparent for one player (Imbrifer's post loooooong ago), making fade filters show for one player only.

So stuff like Quests, multiboard?

but no abilities, units, items,?

You can't create leaderboards/multiboards for a single player either.

You can make things invisible/visible for certain players. Even if it is a 100% transparency for a unit you can do so for local player.

I've seen multiboards shown for only 1 player.

Yes, shown, but not created. A multiboard is a handle object otherwise. Same goes for a special effect, you can't create it for a single player, it doesn't affect gameplay, but it's still a handle object that needs to be synchronised; however, when creating it, you can create it with different modelpaths for different players, making it invisible for some and visible for others.

ahhh, i get it now

Thanks