What to KnowHercules vs. VampiresLA OperaFriday, Oct. 30 and Saturday, Oct. 31The United Theater on Broadway$56-$129 Oct. 30; $81-$161 Oct. 31Mario Bava’s “Hercules in the Haunted World” will screen with live, before-your-ears singers and an orchestra complementing composer’s Patrick Morganelli’s scoreA costume contest featuring a $10,000 grand prize will take place on Oct. 31 (and Oct. 31 only) at the Halloween afterparty; the second-place winner will be awarded $2500 and $500 is the prize for placing thirdThe grand price, second-place, and third-place winners will receive a pair of VIP tickets to a future LA Opera performance, too

Theatrical flair, sumptuous staging, huge productions, strange flights of fancy, and colossal conclusions?

LA Opera has embraced all of the big emotions, famously, all while becoming known for going the distance when it comes to drama.

It shouldn’t surprise any fan of the operatic outfit, then, that LA Opera’s big Halloween night event will not only feature a film that is full of the qualities described above, but a spooky showdown to remember: A costume contest, one that boasts a $10,000 grand prize.

But other showdowns of a cinematic variety are set to take place before the costumes are paraded, and the film-fun face-off is in the title of the atmospheric evening: It’s “Hercules vs. Vampires,” an evening devoted to a “Hercules in the Haunted World” screening at the United Theater on Broadway.

The 1961 Mario Bava-helmed movie features Reg Park, a former Mr. Universe, and horror legend Christopher Lee.

Composer Patrick Morganelli’s thrilling score is a sensation, and to bring the fantastical universe closer to the present-day audience an orchestra and live singers will perform inside the spectacular Downtown Los Angeles theater.

The Spanish Gothic venue provides plenty of grandeur, but so will the costume contest’s grand prize, set to be presented at the Oct. 31 afterparty: The winner of the Halloween night costume contest will be awarded $10,000, “thanks to the generosity of an anonymous donor,” shared the opera team.

The company also revealed that the costume contest winner will receive a pair of VIP tickets “to an LA Opera of their choice (based on availability) and a private tour for two of the LA Opera Costume Shop.”

The outfits will surely be opulent, epic, and highly original, making for a Halloween extravaganza that is truly Herculean in dimension. Check out all of the costume contest rules — participants will need to be 18 and older, for starters — before getting to work on your lavish look.

Of course, there is always the Oct. 30 screening, which will not, repeat, not have a costume contest nor an afterparty, but will include the same stirring singing, orchestral music, and “Hercules in the Haunted World” on the silver screen.

If you already have plans for Halloween night but still want to experience this muscular and monstrous Technicolor treat, a trip to the underworld with a heaping of ’60s-style pizzazz, consider purchasing a ticket for Oct. 30.

Ticket details, cinematic snapshots from the flick, opera-cool tips, and everything you need to know about making your Halloween, or night before Halloween, extra-extra-dramatic, are flexing at this site.