Shrieking Banshees
Start the game by having the players stand around a bonfire in a circle. Tell everyone to look down at the ground. Everyone counts down together from 10. Once you finish counting down, everyone looks up and has to set their gazes at one person in the group. If anyone finds herself sharing a gaze with another in the group, both players let out a shriek and leave the circle. Keep playing until only two players remain in the group.
Nighttime Scavenger Hunt
Before the party, come up with a list of items your guests can find outdoors, such as a maple leaf or pine cone. If you want to make the game scary, have the players look for props you've placed in the yard like fake dismembered hands. Split the players into pairs and give each pair a list of things to find. The pairs race against each other to find the items with only a flashlight to help them see through the darkness. After 10 minutes, bring the pairs back. The pair with the most items wins the game.
Ghost in the Graveyard
Pick one player out of the group to play the "ghost" and head outside to find a hiding spot while the other players count to 100. The players then make their way through the yard, spreading out to find the ghost. Once a player finds the ghost, she screams out "ghost in the graveyard!" This prompts all the players to head back to a designated base point. The "ghost," meanwhile, tries to tag someone. The first tagged player becomes the new ghost and the game continues.
What's That Glowing?
Spread out an assortment of glow-in-the-dark objects outdoors, like glow sticks, before the party begins. Hide the items beneath lounge chairs, within bushes and in trees. Once nighttime hits, everyone heads outside. Immediately, each individual begins searching for as many glowing items as they can find. After five minutes pass, have all the players stop. Have all of the players count their objects. The person with the most glow-in-the-dark objects wins.