Teams: Two teams of 4-5 people each, with 4 people in the field (Pitcher, Catcher, Two Outfielders) at all times.
Equipment: Long, skinny yellow Wiffle® bat and the official white Wiffle® ball, with the oblong holes on half of the ball only.
Playing Area: Baseball-type grass field with foul lines, three bases plus home plate, and a pitching mound. The official field looks like this:

But anyone can develop his/her own field using a park, some baseball gloves or boxes, and a few trees.
Objective: Having fun while scoring more runs than your opponent.
Area of Excellence: The beauty of Wiffle® is in its simplicity and versatility. You can buy everything you need to wiffle at a drug store for about $5 and head to a field. We all remember as kids making up rules about whether the first tree or second tree would be a home run.
Always Rules: Catching the ball is an out? Seriously, there aren’t all that many “always” rules. There are a ton of legitimate ways to play.
Suggested Rules: We prefer requiring the pitcher to put arc on the ball. Others disagree. Both are fun. Pitcher’s hand out makes everything easier. Three strikes and you’re out. Pegging a runner with the ball is great…as long as it’s below the neck. Home runs should be celebrated with a trot around the bases both to get some exercise and because it’s fun.