[scriptless]

Okay, to help you out here.

Not all player variables can be edited client side. Player's x and y can. Player's chat also can. But things like hearts, ap, and mp cannot.

With NPC's when you are doing client side it will only show for the client, and server side shows for everyone. There are some exceptions. When you place bomb explosions for example, or use an on exploded event. These will show for all players. It can be tricky to exactly pinpoint what will, and what will not show for one player, or all others. It's best to experiment.