With every performance 100% plan-free (much less practice!) and imbibed with audience input (and sometimes on-stage participation) - BATS amuses, inspires and, occasionally... falls totally flat :)
BATS describes their shows as PG-13 and risque topics are generally humorous and allusional, more than graphic.
Originally Bay Area Theatersports, and now simply BATS, the non-profit group traces roots to Keith Johnstone and offers a full range of instruction (for children, adults, organizations, etc) in addition to the main performances.
Don't prepare, just show up!
Address: Fort Mason Center, SF
Website: http://www.improv.org