The easiest way to kill an adult Halloween party is to run it exactly like a kids' one: bobbing for apples and a pin-the-tail game. The fix isn't to remove the games, it's to pick the ones that work just as well with a drink in hand as a juice box, and to run the contests like they actually matter.
Make the costume contest a real contest
Secret paper ballots, not a show of hands, turn a costume contest from "whoever's loudest wins" into something people actually try for. Give out more than one award (scariest, funniest, most creative) so the room doesn't just split into winners and everyone else, and run the vote at a set time so people know when to show off their costume instead of hiding by the snack table all night.
Trivia with a little bite to it
A spooky trivia round works for the same reason any good party trivia does: keep it in teams of three or four so nobody's put on the spot, mix a few easy questions in with the ones that spark an actual argument, and read each one twice. A word scramble (same spooky theme) is an easy backup for the table while people are eating.
A scavenger hunt gets people out of their chairs
A list of 15 to 20 spooky things to find around the house or yard works better for an adult party than you'd expect, especially once a drink or two is in. It's one of the few games that gets everyone moving without anyone having to volunteer first.
Give the decorating effort its own contest
If anyone's carved a pumpkin for the party, don't let it go unjudged. Number each pumpkin and run a quick secret ballot alongside the costume vote; it's five extra minutes that makes the person who stayed up carving feel like it was worth it.
Card games for the couch crowd
A deck of Would You Rather and story-starter cards, shuffled into the party at the table where people are eating or between rounds of a bigger game, keeps conversation going without needing the whole room's attention.
Running the night
Set the door scene first (a sign on the door sets the tone before anyone's even inside), then open with bingo and trivia as people arrive. Run the scavenger hunt and card decks mid-party once the room's warmed up, and save the costume parade and the pumpkin vote for a set moment near the end, so everyone's there to see who wins.
Our Halloween Party Games kit has all of this ready to print: eight games, six Halloween Bingo cards, 20 fact-checked Spooky Trivia questions with an answer key, costume and pumpkin contest ballots, a monster scavenger hunt and an Enter If You Dare door sign, for 6 to 40 guests.