From D&D Wiki
When attempting to mate 2 Pokemon, you must roll d100 when you retrieve them. Pokemon need at least 8 hours of privacy in order to make a Breeding Check. For each hour after the required 8 that the the two Pokemon have alone, up to 5 additional hours, you may subtract 2 from your Breeding Check’s roll (up to 10).
- If you roll under 25, an egg is produced. Trainers may only try to make a Breeding Check once
per every 24 hours.
- If you roll under 5, you may flip a coin to choose which parents’ species is passed to the Egg.
Otherwise, the Mother’s species is passed on to the egg. Any moves that the parents know that are on the baby Pokemon’s Egg Move list, once it hatches, are learned. Any moves that the parents know that are on the baby Pokemon’s TM Move list, once it hatches, are learned. Only four Moves may be passed on to the baby Pokemon in these ways.