Bringing a PC over to a new rule system to during a game campaign

Here's something interesting. The guys on the Invictus Stream are playing a game. It started off using the Grimm but is switching to Call of Cthulhu. I've never seen anyone do this for a game before. I think it's an interesting idea. In a way, they really had no choice but to do it this way to run this particular campaign.

The story starts out with the characters as children. No other game system (except for Fate) has stats for kids. In Grimm, your PC is a kid. So I can see why they started out with that. Later on in the story they're adults. Grimm doesn't have stats for adults, hence the switch. Also, the game was always meant to be a Call of Cthulhu game. It doesn't have stats for kids.

Have any of you done this for a game?

a reply to: Skid Mark

uhhh... D&D handles this with a Template.

The child template.

www.dandwiki.com...(3.5e_Template)

And while i haven't played as a child. I did play a campaign where we played 14-17 year olds.

Our gm adjusted a few stats. And we played just fine.

a reply to: grey580

Cool. I had no idea they had kid stats. Thanks.

a reply to: Skid Mark

no problem.

Generally thinking, you could just lower the stats that would be affected by age, regardless of game system. (and some others, like Dexterity), may be higher.

a reply to: Gazrok

Cool! Thank you.