  We investigate how the formation and evolution of extrasolar planetary
systems can be affected by stellar encounters that occur in the crowded
conditions of a stellar cluster. Using plausible estimates of cluster
evolution, we show how planet formation may be supressed in globular clusters
while planets wider than 0.1 AU that do form in such environments can be
ejected from their stellar system. Less crowded systems such as open clusters
have a much reduced effect on any planetary system. Planet formation is
unaffected in open clusters and only the wider planetary systems will be
disrupted during the cluster's lifetime. The potential for free-floating
planets in these environments is also discussed.
