Error with while true do loop?

You basically had a bunch of the same error in your script. I'll go ahead, and post the fixed script first, then explain it a bit.

Here it is:

while true do
	local Gamestart = workspace.Gamestart
	local Intermission = workspace.Intermission
	local Inttime = workspace.Inttime
	local Resources = workspace.Resources
	Intermission.Value = true
	repeat wait(1) --Repeats following code every second
		if Inttime.Value>0 then
			Inttime.Value=Inttime.Value-1
		end
	until Inttime.Value<=0 --Stop repeating once it hits 0
	if Inttime.Value == 0  then
		Intermission.Value = false
		Inttime.Value = 30
		wait()
		Gamestart.Value = true 
		if Resources.Value == 0 then
			Gamestart.Value = false
			local plrs = game.Players:GetPlayers()
			for _, player in pairs(plrs) do
			    if player.Character and player.Character:FindFirstChild("Humanoid") then
			        player.Character.Humanoid.Health = 0
			    end
			end
		end
	end
end

So basically, the error you had was that you were defining the Variables: Gamestart, Intermission, Inttime, and Resources, as their Values. When you do this, the script stores the variable as what the value of it was at the time it was called.

Here's an example:

local ValueExample=script.Parent.Value --Let's say this comes out as true
script.Parent.Value=not script.Parent.Value --Changes the value to false
print(ValueExample) --Would print out "true"

This would happen because the value is being changed correctly, but as I already stated, it is storing the value, not the object that you need to access to change it's property.

To fix the above script, we would do this:

local ValueExample=script.Parent --Let's say this is true again
script.Parent.Value=not script.Parent.Value --Changes the value to false
print(ValueExample.Value) --Would print out "false" this time

This time we accessed the object, and were able to change it's property correctly, so the script worked out how we wanted it to.

Anyways, I hope this helped you out a bit. If you have any problems/questions, please leave a comment below :P