it's a server script in the ClassicSword. Should I change it to a local or server script service?
game.Players.PlayerAdded:Connect(function(plr)
plr.CharacterAdded:Connect(function(character)
if plr:WaitForChild("Backpack"):FindFirstChild("ClassicSword") then
plr.Character.Humanoid.JumpPower = plr.Character.Humanoid.JumpPower + 99999
end
end)

3 comments
According to the dev hub tools can be both a local script and a server scripts
Is there a reason why this script isn't working?
It should work...