Of course basketball can be played indoors. Many public courts are actually built in indoor gyms. There are many small plastic basketball sets for younger kids to use in the house. Additionally, there are a number of hoops for indoor use that can be mounted to hang off the top of a door or stick to the side of a wall. It’s great that basketball can be played indoors to combat weather or be able to keep an eye on the kids from the comfort of your home.