Thread:Knj00/@comment-9423155-20130511230027/@comment-5089372-20130513024245

The Breeding Cave upgrade the (Enchanted Breeding Cave) reduces the breeding time of a dragon by 20%. It does not increase odds of getting special dragon.

Now the chances of breeding epic dragons, gemstone dragons, opposite dragons, and limited dragons are slightly increased using the Epic Breeding Island. The upgrade for it (Epic Breeding Sanctuary) just reduces the breeding time of a dragon by 20%, like the Enchanted Cave.

Yes I have tried it (the one for 100,000 coins) many people say it doesn't work but I believe it has helped me get more rare dragons. In most cases though not the rare I want. Just the rares with high breeding times so I really don't use it anymore. That is my experience with it though, it's different for different people.