Full-contact box fort building
Maybe the greatest thing to happen to San Francisco since this, Ultimate Team Cardboard Fortress Battle is a full-contact game of capture the flag going down this Saturday in Dolores Park, where flags are hidden in (yawn) cardboard box forts
Here's how it works: You and 11 of your similarly shirted friends (Team Sleeveless Mock Turtlenecks!) show up with the UTCFB essentials (masking tape, cardboard, a recognizable flag & a stuffed animal mascot), build an impregnable box fort/castle/New York-style loft, and hide the flag inside of it, with the stipulation that it isn't concealed in a taped-up box
Then, following 2min "Braveheart-style" speeches by each team's respective "Generals", you'll get down to actual gameplay: alternating 5min rounds of a) trying to find the flag while gently shoulder pinning your opponents to the ground (3sec pin by you = 120sec in the penalty area for them), and b) rebuilding your fort, re-hiding your flag, drinking Dolores Park-approved beverages, and wondering why your recesses were never this f***ing awesome
The battle is won when your opponent's fortress is in ruins and their flag has been brought to yours -- which you'll likely only manage if you can catch the other team (yawn) sleeping.