After running a simplified game of Warhammer 40K for my nine year old nephew I realized he was enjoying the game, and could read the tables...but the difference between a 2+ and a 4+ on a D6 wasn't really clicking. I decided to design some combat really quick so we could try another angle.
I designed these and ordered them from Gamecrafter. Pretty cheap and quickly received.
While I haven't drummed up rules completely yet, the mechanics will be pretty simple. A Space Marine rolls one dice when shooting - the target rolls dice equal to his armour (mostly one die), a shield blocks it.
The red skull/strike is a critical hit - perhaps this will ignore armour for certain weapons or auto-kill (ie. a meltagun may incinerate it's target if a critical hit is rolled etc.). The blue magic swirl will be used for Librarians and Farseers etc. Perhaps a Farseer will be allowed to use a magic result as a shield. Psykers will likely roll a couple of dice, requiring a magic result to issue a simple spell etc.
I picked up two opposing sets of matching dice. I think this approach will be a bit easier - much more "Hero Quest" than Mathhammer.
Here is a link to the dice if anyone wants to pick some up for gaming with younger gamers, or even introducing friends to super-simple wargaming: