  While humanity has not yet observed any extraterrestrial intelligence (ETI),
contact with ETI remains possible. Contact could occur through a broad range of
scenarios that have varying consequences for humanity. However, many
discussions of this question assume that contact will follow a particular
scenario that derives from the hopes and fears of the author. In this paper, we
analyze a broad range of contact scenarios in terms of whether contact with ETI
would benefit or harm humanity. This type of broad analysis can help us prepare
for actual contact with ETI even if the details of contact do not fully
resemble any specific scenario.
