click on each of the boxes on the parents sides, type the name of the trait (no capital letters!) and repeat. When all boxes are filled to your liking, click the randomize button; this mixes the traits from both parents and some random traits. Scroll down to see how it works (simplified) So, there are 3 initial numbers that get randomized from 1-10. If they land in between 1-6 (each of the parent traits) then it gains a parent's trait. If the number is 7-10, then it randomizes from all possible traits.