This works really well, but you need to have an actual offer for this to work. Otherwise it's a bluff and if they call it, you end up with the same salary and

This works really well, but you need to have an actual offer for this to work. Otherwise it's a bluff and if they call it, you end up with the same salary and on a list of unreliable employees. Obviously, you need to be very tactful and polite when asking for a raise, and generally blame it on financial/life circumstances beyond your control that force you to look at other companies despite of really liking it here and never wanting to leave otherwise... or some such.