[hellbanner]

http://www.peachpit.com/store/game-mechanics-advanced-game-d... has an online editor for storing values in containers, then with rules for moving those values eg.

every turn, +1 food every turn, 50% chance of .. etc

it's pretty detailed, worth looking into

[kneeko]

Agreed, it's an excellent book. The Machinations tool is available here: http://www.jorisdormans.nl/machinations/