You are referring to an International Driving Permit, which is not a license. Rather, it acts as a translator for your actual license. Obtaining one will cost you $20.00; will last a year; is valid in most countries; and only takes minutes to acquire. You will also need a passport-sized photograph of yourself.

You are required to have an International Driving Permit when driving in Romania. I found this surprising; but when I drove from Serbia to Romania, agents of the border patrol not only requested that they see my International Driving Permit — which I thankfully had — but also told me about three other motorists that they turned away from the border that day because they did not have an International Driving Permit.

The biggest problem you might have with driving in Romania is finding free parking, which is not impossible to do. Otherwise, I would recommend driving in Romania.