rules for toy gaming

Hi all, I am writing on behalf of my young son. He loves transformers, and has seen both movies and has loads of toy transformers to play with. As much as he like bashing them about in a childlike manner, he does also ask if there are any rules to play with them, like wargames rules, with dice or cards or whatever.
If you can give us any ideas or point us in the right direction, we would be grateful
Thanks
Scott and Chris
If you can give us any ideas or point us in the right direction, we would be grateful
Thanks
Scott and Chris