It has long been known that enlargement would have dramatic implications for EU decision-making: a structure designed for six would simply collapse under the weight of 25 or more members. This is why EU leaders have been searching for a viable voting-system reform, which will be discussed again in June 2004. This policy brief studies the many options facing EU leaders. Using the Normalised Banzhaf Index, it provides quantitative estimates of the decision-making efficiency and distributions of power for the various schemes proposed. Insight is offered on how aspects of different voting rules affect member states. Finally, it considers how the flawed voting system set out in the Nice Treaty could be repaired, enabling a respectable level of decision-making efficiency and almost no change to the power distribution agreed at Nice.