Board Thread:Dragon City Gameplay Questions & Answers/@comment-184.97.38.120-20130625224528/@comment-10760902-20130626171524

every legend dragon (legendary, wind, crystal, mirror) has same chance to get. So when ever you breed a pair of rare hybrids, you have a particular chance for legend type, and 1/4 of that chance is shared to every legend.

Anyway, best chance to get all legend is using  Soccer & Cool Fire (best rate at <50, about 26.67% for all legends and 6.67% each legend)
 * Soccer + Soccer
 * Soccer + Cool Fire
 * Cool Fire + Soccer