Oil-rich developing countries that are sufficiently democratic to have electoral competition are becoming far more common. High oil prices are making oil more important than ever to existing oil exporters' economies, discoveries of new deposits are allowing other countries around West Africa and Central Asia to also benefit from the oil revenues. Finally, the continuing global pressure to introduce democratization, notably in the Middle East, is bringing electoral competition to some traditionally autocratic oil economies. This paper presents evidence that oil-rich developing countries are particularly ill-suited to electoral competition unless it is complemented by unusually strong checks and balances. To date, this has not been the case in the oil-rich societies, which have weak checks and balances, even by the modest standards of developing countries.