This chapter takes Switzerland’s much praised three-pillar system to illustrate some of the challenges pension system reforms face in an ageing society. It shows that policymakers are confronted by some individuals with behavioral anomalies, and by others who strategically exploitthe system. The trade-off between proviing ncentives and adequate retirement income lmitsplicy options, especially if reformers do not want to impose too many restrictions on individualchoice and avoid excessive burdens for the young generation. Pension reforms can also be seriously challenged by political constraints, in particular, when voters have a direct say onproposed changes.