Creating your Sim's personality
Our next port of call is to fill up our chosen vessels with a hodge-podge of character traits that will imbue them with a sense of personal identity that can then be deliberately at odds with other household members for a bit of excitement or compliment them perfectly to avoid any conflict. You'll just have to rely on appliances blowing up and rogue flames from an open fire to create the drama for you.
The mysterious collection of hexagons plastered with equally mysterious question marks is of course where we begin. The large one on the left is your Sim's Aspiration and will serve as their lifelong goal. It can be changed later on so don't give yourself a hernia deliberating over it.
There are 10 categories to choose from but you'll need to narrow it down from the subsets within them. Once you pick an Aspiration, you'll be granted a bonus trait associated with that category. In this example the Love Aspiration grants the Alluring bonus trait, making the Sim more successful in romantic scenarios than those without the trait.
Each adult Sim can choose 3 traits from 4 categories. There are 9 Emotional traits, 6 in the Hobby category, 11 under Lifestyle and 9 Social. These choices will govern the behavior and desires of your Sim and will dictate their compatibility with others. Throwing a good Sim and an Evil Sim into the same household will most likely result in domestic drama, as would making a neat Sim share a house with a messy Sim.
It's also worth noting that Sims are affected by their environment and what's going on around them. A neat Sim will be unhappy if there's a mess lying around. A slob Sim actually makes things dirtier faster than a Sim without the slob trait so the dynamic between 2 Sims with those traits would differ to any other combination. Think of it as a domino effect between what upsets a Sim and what makes it happy and you should be able to engineer all sorts of interesting scenarios just by pairing up the right personality types together.