I thought of something like this - I can see the Outdoors storyteller trait working as a useful trait to put into it - but it should have some new skills such as storytelling, imagination or creativity, and work in the logic skill too. However, this is probably something fairly easily modded - perhaps something I should work on. We already have a game table and using dining tables - which can already be set for specific things - can be useful. We basically need a dice rolling animation and some polyhedral dice objects. If I can find the animation, I might take a hand at it.
I've modded a fairly successful mod for Civ 3 years ago that had a bunch of elements incorporated into Civ IV - but with the Sims all I've managed to do so far are a few recolors - I suck at modelling things, but scripting I should be able to do - have modded my own cheats into several strategy games.