Monster Breeder Reference
As monsters age and grow stronger, their potential will eventually be met and it will be time to splice them. You may splice yourself with a monster or you may dual-splice two monsters. Splicing will reset your monster's level but retain most of the stats, meaning their child can gain stats for much cheaper SRP costs. It's also a valuable opportunity to inherit great moves from other monster types.
Note: In order to stop very strong monsters from growing too strong, a system has been put into place. For all monsters over 250 combined stats, you will gain very slightly less. For those over 500 combined stats, you will lose a good amount. This is because a 5% increase of 100 is 5, and a 5% increase on 200 is 10. This only affects dual-splicing with a great or perfect rating.
Single-monster splicing is a bit different but generally the same. You sacrifice health and a crystal in place of the second monster to be spliced. How much you sacrifice -- max of 50% health -- along with the crystal strength, is how much of the monster's stats will be retained. It is possible to sacrifice 50% health and buy the best crystal and have a monster with slightly better stats than when you went in. Note a monster cannot inherit other types' moves in this manner.
Playing the Game