Trait is a personality system in The Sims 4, similar to the trait system in The Sims 3. The personality system as a building block of Sims in The Sims 4 is a combination of trait from The Sims 3 and aspiration from The Sims 2. There are three kinds of traits in the game: normal traits, bonus traits, and reward traits. Each kind has different ways to earn them.