There is no rule that bachelor and bachelorette parties must be held separately. The members of both parties can get together and play games or go out on the town for the evening together. While socializing together either at home or at the bars, there are games that the members of the combined bachelor and bachelorette party can play together.
Have the guests of your combined bachelor and bachelorette party form teams. Create a list of wedding-related items and assign points to each item. Give each team a digital camera. Some of these items can be collected physically, but others will have to be photographed. Some places to photograph could include the church that the wedding is scheduled to be held at, the reception hall and the rehearsal dinner location. Items that the teams will need to collect could include a wedding invitation, a garter or a unity candle. All of these items can be assigned points based on the level of difficulty you feel is involved in collecting each item.
Spin for a Dare
Purchase a spinner or create your own with a variety of dares on the spinner. Some of these items could include dancing with the person that asks you to spin the spinner, drinking an alcoholic beverage, giving the person that asked you to spin the spinner a hug or a kiss, and dancing with the bride and her entire bridal party. The spinner can be spun by members of the combined bachelor and bachelorette party. The members of the party could also each take turns presenting the spinner to a stranger and asking him to spin it and perform the action the spinner lands on.
Name That Drink
Create a list of between 10 and 15 popular drinks. Instead of listing the names of the drinks, only list the ingredients and amounts of each ingredient needed to make the drink. Once you have assembled the list, give it to each guest at the party. Ask each of the guests to fill in the name of the drink above the ingredients. Once everyone has filled in their guesses, instruct the guests to exchange answer sheets. Reveal the answers and score each sheet based on the number of correct answers. The member of the combined bachelor/bachelorette party who gets the most drinks correct wins a door prize.
Drink If is a game where there are a number of qualifications listed on a sheet of a paper. Choose someone to read these periodically during the bachelorette/bachelor party. Anyone that has done the action that is read out loud must drink. Spread these out during the evening, especially when drinking has slowed down for the evening. If someone claims he has not done something, but another guest can prove that he did, the guest who denied doing the action must drink twice.