Hello Dragon Masters,
to help you breed strategically given the recent updates to Breeding, we have compiled some information to share with you on how breeding works as of today (March 2021) :
If the selected parents have a high rarity and/or are empowered, you will have more chances of obtaining the dragons in the possibility pool with the highest rarities.
Moreover, if the rarities and stars are high enough you might unlock better possible dragons to receive as children (this is the green bar that you see when you select 2 dragons on the breeding screen). High rarity and empowered dragons give a boost to the chances of obtaining dragons with the 2 highest rarities in a child possibility pool.
Note: If unlocked and activated, the Phaun Tower applies an additional multiplier to the weights of those dragons. Specifically, it multiplies the weights of the dragons with the 2 highest rarities by 3.
Whenever you breed 2 dragons, there are several possible child outcomes. These outcomes are dependent on the elements of the parents selected.
First, one element is picked from each parent, and then a dragon is selected from the child possibility pool for these two elements. Only 1 element from each parent is selected during breeding. This means that the more elements the selected parents have, the more possible element combinations, and the larger pool of potential outcomes.