The Sims 3 takes The Sims to another level of entertainment for the series and sets up the future for further additions as well. In The Sims 3, you can begin single or enter the world of The Sims 3 with a family and friends, you get to decide. Adding a family and friends to your new Sim's life is as easy clicking on the Add a Sim button to begin building a new Sim. You can choose to work in any age group, from toddler to elder, and build up a massive clan or just decide on a simple couple beginning life in Sunset Valley.
The fastest way to grow your new Sim family is to have a child. Once you have created two Sims of adult age and the opposite sex, you can choose to have them "hook-up" and have a child together. The basic laws of genetics still apply and you can expect your physical attributes to be passed on to your child.
To create a child using two adult Sims of the opposite sex, select the "Make a Child" option, which will bring up a window with all of your available adult Sims. Choose the parents for your child from the available choices and the child will appear below. You can even choose to age your child right away and add it to the household. Obviously, it's no longer your child after you do this, but the possibilities become amazing.
After you have created a second Sim or variety of Sims, you can begin assigning the relationships between the Sims. You can choose a basic designation of 'housemates' for the relationship between two Sims, but if you decide not too designate, the game will assign one for you. You can choose to make two adult or young adult Sims spouses (different genders isn't a requirement for spouses in The Sims 3) and assign younger Sims, like teens or children, to siblings.
In The Sims 3, your Sims will age as they do in real life, only at an accelerated pace in order to make the game a little quicker than real life. Your Sims go through a number of different stages of virtual life in The Sims 3, each stage lasts a certain amount of days in the game, before you go onto the next stage.
- Toddler: 7 days
- Child: 7 days
- Teen: 14 days
- Young Adult: 21 days
- Adult: 21 days
- Elder: 16 days minimum
When a toddler ages into a child, the Sim earns an extra trait to help determine more facets of their deepening personality. You gain one for each stage of life until your Sim reaches the Young Adult stage, and the five maximum traits a Sim is allowed in The Sims 3. Traits are carried over from the young adult through the elder stage until a particular trait becomes incompatible with your Sims new age. The final stage of life for a Sim, the elder stage, does result in death, but as long as there are children in your household, your household will continue to thrive.