Haunted Hill 5-10k West Portal Playground, 131 Lenox, SF. (510) 681-6181, www.tinyurl.com/hauntedhillwestportal. 5-8pm, free. Assemble a team of up to five of the most adventurous people you know, slip on some comfy shoes, and hit the trail of this scavenger hunt in the West Portal neighborhood. It's like trick-or-treating for adults.
Rin Tin Tiger, Doe Eye, Steelwells, Wes Lesley and His Deadly Medley Bottom of the Hill, 1233 17th St., SF; www.bottomofthehill.com. 9pm, $10. The third annual "Haunted Hoedown" brings a hayride-full of rock goodness.
Safety Meeting Club Six, 66 Sixth St., SF; www.clubsix1.com. 10pm-4am, $10. before you go trick or treating, you need a safety meeting — a dangerous local techno safety meeting, that is, with DJs Robot Hustle, Doc Sleep, Taco Tuesday, Justime, Cindy99, and a live performance from Exillon and Dabecy.
Spiral Dance Kezar Stadium, 755 Stanyan, SF; www.reclaimingspiraldance.org. Doors 6pm, dance 7:30, $20-100. The Reclaiming Collective holds Spiral Dances all year round, but the Halloween dance is their biggest hit. But the dance isn't for Halloween — as the collective explains, "The holiday popularly known as Halloween is the time of year known to witches as Samhain, when the veil is thin between the worlds of the living and the dead." Celebrate the Beloved Dead and get lost in the dance with hundreds of others in Kezar Stadium.
Trap City: Hell's Eve Edition Icon, 1192 Folsom, SF; www.facebook.com/trapcitysf. 9pm, $10. The purple swag and gold chainz hip-hop party gets fiendish with Heroes X Villains, Hi Topz, Bogl, Ultraviolet, Napsty, Facemelter, more.
True Blood Halloween Herbst Pavilion, Fort Mason Center, SF; truebloodhalloween-solyluna.eventbrite.com. 9pm, $30–$80. Massive Halloween club night in the 30,000 square foot space, with EC Twins, Dorman Doray, and Sex Panther, along with vampires, werewolves, zombies, and probably lots of sexy nurses.
The Uptown's Halloween Bash 2012 Uptown, 1928 Telegraph Ave, Oakl; www.uptownnightclub.com. 9pm, $12–$15. Titillating terrors are promised at this burlesque of happy horrors, with the gorgeous Hubba Hubba Revue in full undressed effect, music by the Deadlies, and much more surf-goth fun.
The Cabinet of Dr. Caligari and Nosferatu Tannery, 708 Gilman, Berk; berkeleyundergroundfilms.blogspot.com. 7:30pm, donations accepted. The two biggest silent horror films (from 1921 and 1922, respectively) in a double-feature that'll haunt your nightmares.
Haunted Honey Holy Cow, 1535 Folsom, SF; www.honeysoundsystem.com. 9pm, $5. The naughty queer underground house boys of Honey Soundsystem throw one of the best weekly parties in SF. And tonight they'll do it in costume. You can do it in costume, too!
Spooktacular Halloween Party & Trick or Treat in Japantown Japantown Peace Plaza, Post and Buchanan, SF. (415) 567-4573, www.sfjapantown.org. Noon-4pm, free, all ages. Halloween, Japanese-style, with unique arts and crafts, a bounce house, and trick or treating at the East and West malls.