Void Teleport to spawn

[NiLSPACE]

A simple

function OnPlayerMoving(Player)
    if (Player:GetPosY() < 0) then
        local World = Player:GetWorld()
        Player:TeleportToCoords(World:GetSpawnX(), World:GetSpawnY(), World:GetSpawnZ())
    end
end

Also, don't forget to add the hook on initialization of the plugin:

cPluginManager:AddHook(cPluginManager.HOOK_PLAYER_MOVING, OnPlayerMoving);