For example, if making a survival game. The player only has 4 important stats: 1. Life 2. Sanity 3.Hunger 4. Thirsty Don't combine the stats into one class. Separate them into different class. Then let the stats drive the gamer looking for food, collecting materials. If you made food cooking process very complex, that's good design. It is not considered as mechanic, it can be considered as one part of the details. The gamer want to learn complex cooking process because of hunger (it's mechanic). So simple mechanic drive the gamer into the complex details. I hope my explanation is useful.