Roblox is starting with 40 of its most popular characters, including Builderman. The 2½-inch-tall plastic figures, which roughly resemble Lego figurines, will have interchangeable body parts ...

A parent’s first glance at kids playing Roblox can be bewildering. They steer their little avatars at a frantic clip while tapping out bursts of competitive poppycock to one another via chat.