| L.A.con I, the 30th World Science Fiction Convention | |
| Venue: | International Hotel |
| Dates: | 1–4 September 1972 |
| Filing: | Non-profit |
| Attendance: | 2,007 |
The 30th World Science Fiction Convention (Worldcon), also known as L.A.con I, was held on 1–4 September 1972 at the International Hotel in Los Angeles, California, United States.
The organising committee was co-chaired by Charles Crayne and Bruce Pelz.
Attendance was approximately 2,007.
The 33rd World Science Fiction Convention was awarded to Aussiecon I in Melbourne, Australia. This was the first time a Worldcon was awarded to a site outside North America or Europe.
At the L.A.Con I masquerade, one of the contestants, artist Scott Shaw!, came on stage wearing only a bathing suit, with his body completely covered with crunchy peanut butter. The name of his costume was "The Turd." from an underground comic story Shaw wrote and illustrated. Since some of the peanut butter tended to drip off of him, making the floor sticky for other contestants, a rule was passed that forever after at science fiction convention masquerades, no peanut butter costumes would be allowed. This masquerade rule is universally known among science fiction fans as the "no peanut butter rule."
The first video game competition at a science fiction convention was held, and a science fiction fan named Kevan Pritchard from Lawndale, California, won the world championship contest in the game Spacewar!.