Upgrade your breeding facilities until the advanced breeding lab becomes available. Use its foal simulator to compare possible outcomes for your mare and stallion before you breed. A preview helps you decide whether the pairing suits your goal.
Work toward the advanced breeding station
The official Steam description lists foal previews as an advanced building feature. Check your yard's building upgrade options for the next step toward the lab.
Change one parent at a time
Choose a pair to preview, then compare it with one alternative. For example, keep the mare and change the stallion if your goal is a particular coat or a stronger performance prospect. Holding one parent constant makes the comparison easier to read.
Decide what you value before comparing
Pick the outcome you care about, whether that is appearance, potential or temperament. Use the preview to narrow down your choices, then check that you have room for the foal and time to care for it.
FAQ
Can I use the simulator as soon as I start?
The simulator is part of the advanced breeding lab. It comes through building progression.
Does the simulator pick the parents for me?
You choose which prospective pairing to examine.
Does the preview guarantee what will be born?
The lab previews possible foals. Use it to compare options before deciding.