"As you tend to your sim’s specific needs - comfort, hunger, social, bladder, etc – you’ll be compelled to try new things and build skill points in different categories like mechanical, creativity, body, and stuff. And as you build up the skills of your sim it will become better at doing things, anything from making more nourishing meals to fixing broken appliances quicker (and with less chance of horrific electrical shock, too), as your sim excels at these things you will be rewarded with varying levels of remuneration. Most rewards come in the form of new household items to play with and use, but more substantial success will yield far better results like new modes of play, for example."