How Much Planning Time Is Required?
It depends on a number of factors, including the details of the game, the number of players, and how much effort you want to put into it. In general, you'll want to give yourself at least two to three weeks to plan and prepare for the party. Think about how much time will be required for the following:
Selecting and Purchasing the Game - If you're purchasing a downloadable game, this may only take an hour or so. If you're purchasing a boxed game, then you'll need to take into account shipping time.
Preparing the Game Supplies - If you purchase a boxed kit, it should include everything you need, ready to go; a downloadable kit will require you to print and organize the game material.
Sending Invitations - Whether you're mailing or hand-delivering your party invitations, it will take some time to address the invitations and envelopes, and to choose a character for each person, and to include a character description along with each invitation.
Decorations and Costumes - This is optional, of course, but using decorations, props, and costumes that match the theme of of the game can go a long way towards making a fun and memorable experience. You'll need to either make or purchase appropriate decorations, and each guest will need to either make or purchase their own costume.
Food and Drink - Planning, procuring, and cooking a meal or snacks takes time, but foods and beverages that match the theme of your party can really help to establish mood and atmosphere. Many games come with recipes or menu suggestions to make this part go smoothly.
Preparing To Host The Game - As host, you'll need to familiarize yourself with the rules of the game, as well as a timeline for your party. Don't worry, most games include a comprehensive host guide that will help you through all the steps.
In reality, you can spend as much or as little time as you like on preparation, but realize that taking the time to do thing right usually results in a more successful and satisfying event.