How does someone Restart a game after someone dies?

I cannot really help you with the lack of detail in your request, but I can at least try.

game.Players.PlayerAdded:connect(function(p)
    p.CharacterAdded:connect(function(c)
        if c:WaitForChild("Humanoid"):GetState() ==Enum.HumanoidStateType.Dead then
            print("Dead")

        end
    end)
end)

In this code, we run off of the PlayerAdded event. The parameter "p" is the player. Skipping a line, we check to see if the Humanoid's state is "Dead". If true, then the server prints "Dead" to output.

Again, I can't really help you without seeing what you are trying to do exactly, but I hope this helped a bit!