1) Mensa membership begins around 130-132 IQ, 98th percentile... moderately gifted.
2) Events are largely run by volunteers... can vary widely from year to year.
3) Regional Gatherings,
Annual Gathering, and
Mensa Mind Games may be of interest.
4) There is a membership fee, ranging from annual membership to lifetime membership based on age (higher cost for younger members whose anticipated remaining lifespan is longer... therefore the lifetime membership covers more years of annual dues). A one-year membership may not be long enough to get the flavor of the various offerings. A 3-year or 5-year membership may allow ample time to sample opportunities.
