My daughter is 4, and she is very intrigued by what D&D is. She sees me prepping, the minis, the maps, the book, and she is dying to play. I created a lite version of an rpg to play with her, called rpgkids. It uses 2 dice, a d12 and a d6. It's basically an exercise in number recognition and simple arithmetic for her, desguised as an rpg. She thinks she's playing D&D though, as it uses minis and tiles and all that good stuff. Check it out. If any of you guys are parents that have been wanting to introduce your small ones to rpg's, this may fit the bill.