In episode 34 of the Gweek podcast, I mentioned Lego Heroica and how much my 8-year-old daughter enjoys it. It's a simple-rule-set role playing game that uses Lego pieces for the characters, board, and even the six-sided die. We have the 101-piece Draida Bay ($14.99 on Amazon).
It took Jane about 15 minutes to put the board together and we were off and running. Jane played the barbarian (special skill: kill all adjacent monsters) and I played the wizard (can kill a monster up to four squares away, including around corners). Our quest was to defeat the Goblin General and make off with his beloved Golden Crystal of Reflection. Game play was about 10 minutes.
The Heroica line consists of four different games, which connect together to form a super Heroica game. Draida Bay is the smallest of the four games. There's also Waldurk Forest, Caverns of Nathuz, and Castle Fortaan. The complete series connected together looks like a lot of fun. I know what I'm getting Jane for her birthday in a few months!