Hi,
I just want to check. If I wanted to change the GUI for everyone in the game, would this be my best option? I am using it for a Minigame that needs to change the gui.
for i,v in pairs (game.Player:GetPlayers()) do v.PlayerGui.ScreenGui.TextLabel.Text = 'This is a test' end
please do note that I am typing this in chrome so if there is any error, I apologize ahead of time.
Your best option would be making a RemoteEvent in ReplicatedStorage, then call :FireAllClients() on it to let the clients know what to do. (it takes arguments so with that you can specify actions)
Then on every client you put a LocalScript which gets these OnClientEvents and manipulate the GUIs themselves. This follows the idea of the client servermodel.
Tutorial on Remotes: http://wiki.roblox.com/index.php?title=RemoteFunction_and_RemoteEvent_Tutorial
(but the way you do it now would also work if FE isn't on c;)