These Building Block Kits are designed for yougsters from age 4-1/2 up who are really starting to use building blocks to start block building. Typically, they discover these big school size blocks at quality day care centers or preschools. People who have grown up with blocks often describe them as "The best toy we ever had!" Kindergarten teachers often cite these as the best single all around toy. These sets are too big for a 3 year old unless exceptionally precocious. Better to buy a smaller set and work out a plan for playing with your child. The Beginner A is our most popular set.