The best part of attending any Halloween party, besides the fun of getting all dressed up in your favorite costume, is the wonderful assortment of games that are a key part of the Halloween party tradition.
If the party contains both children and adults, divide the guests into two teams and have a challenge contest to Create the Best Scarecrow, providing both teams with straw, assorted clothing items like shirts, pants, straw hat and gloves, along with paint to create a face. Another good challenge contest for two teams is a Halloween version of the Easter egg hunt, except for this game, both teams will be hunting the party grounds, inside and out for small ghosts cut out of white cardboard or ghost lollipops hidden ahead of time, with the team finding the most "ghosts" winning the prize. You can also hide a special silver or gold wrapped ghost to award the winner with a carved jack-o-lantern prize.
Bobbing for Apples is a time-honored Halloween party game that suits adults and children alike. Just make sure you have a big enough tub to hold your apples in water (red delicious and green Granny Smith work best), and make sure that every apple has a stem that the contestant can grab onto with their teeth.
A neighborhood scavenger hunt is appropriate for an adult party so long as you allow enough time and have items on your list that are actually accessible like pine cones, autumn leaves and coins with a specific year noted.
Guess the Gross Food is always a popular game for all ages, so long as contestants don't have hidden allergies. Blindfold the person, then have them sample and identify things like pirate blood (liquid gelatin), dead man's eyeball (frozen grapes) and the Mummy's brains (mashed bananas).
Small children especially like games of Catch the Candy. Hand each participant a plastic pumpkin, then have all of them at a special line as you toss wrapped candy into the crowd which they must catch inside their pumpkins. They get to keep their pumpkins and all the candy they can catch inside.
A good game to end the evening's festivities and challenge people's creativity is a Ghost Story Telling game, challenging anyone who wants to tell the best ghost story, with a panel of judges selected ahead of time to pick the winning tale from all of those presented.