How can I fix my script that is supposed to explode the player?

Problem:

There's no need of the wait on line 1, since the player would already have been in the game. I can't see any really see any errors within your code but try this code

Fixed Code:

local function explode()
    local player = game.Players.LocalPlayer 
    repeat wait() until player.Character
    local handle = player.Character:FindFirstChild("HumanoidRootPart")

    local explosion = Instance.new("Explosion")
    explosion.Position = handle.Position
    print("Exploded")
end

explode()

Ensure this is a LocalScript placed in StarterPlayer < StarterPlayerScripts

Recommendation(s)

• Use HumanoidRootPart when working with events like this, because let's say an R15 rig joins the game it wouldn't work because R15 don't have a torso
• FindFirstChild is better (in this case) because WaitForChild yeilds until the thread exits whilst FindFirstChild finds the child of the given instance immediately unlike WaitForChild.

JesseSong