One of my main debates regarding Dragonvale's breeding has always been how the odds exactly work. We know we have normal breeding results and also rare results. While determining the absolute odds of obtaining a specific dragon as the result of breeding would require extensive work (which hypothetically could be done with enough manpower), we can however deduce an approximation by doing repeated trials. Here's how it went down.

1. My girlfriend and I both did 100 breeding trials using a level 10 BRASS on the left and a level 10 STORM on the right.
2. We used the Epic Breeding Island.
3. We kept track of the specific order in which the dragons hatched.
4. The possible results of breeding a BRASS and STORM dragon are: Brass (5 hrs), Firefly (3 hrs), Magnetic (4 hrs), Mine (10 hrs), Scorch (3 hrs), Storm (5 hrs), Steel (14 hrs), Sun (48 hrs), Moon (48 hrs), and Rainbow (48 hrs).
5. Since we did these trials during the day, we had a 0% chance of breeding a moon dragon. Therefore, Moon is not really a possible outcome.
6. As a result, there are 9 different possible outcomes of breeding a BRASS and STORM dragon.

It's important to note the effect of a limited number of trials on the outcome of the test. The closer to infinity N becomes (N is the number of samples), the closer the result will resemble a bell curve. Therefore, with limited trials, the result will not perfectly reflect a bell curve and thus all one can do is estimate.

Without further ado, here are the 100 trials for both of our experiments.

• My girlfriend got a rainbow dragon on her 102nd trial.

So, what can we draw from these results? First off, we should discuss the different possibilities as far as probability goes. The first scenario is where the number of possible outcomes when breeding two dragons is the only determinant of odds. For example, say there are four possible offspring as a result of breeding. Do each have a 25% (1 in 4) probability of getting bred? The other scenario is where each dragon has a specific probability assigned to them by the developers. For example, you may have four potential offspring but each offspring have different odds, say, 25%, 50%, 12.5%, and 12.5%. This is what I'm leaning toward right now but I'll look into it more later. Here are the results of the 100 trials.

So here are some conclusions I came upon after doing this research:

1. If you need Steel (which is Cold + Metal) this is a great way to get one. The other potential outcome of breeding Cold + Metal is the Mine dragon.
2. The probability of getting a Rainbow is probably about 1% or 1 in 100. I would say across the board, the probability is most likely less than 5%.
3. The number of times my girlfriend and I got each dragon (Frequency in the chart) is very close. This suggests to me that the odds for each dragon are set by the developers. For example, we have six common breeding results: Brass, Firefly, Magnetic, Storm, Mine, and Scorch. We have three rare breeding results: Steel, Sun, Rainbow. Breeding a BRASS (metal, fire) and STORM (cold, lightning) give a few possible matchups of elements: Metal+Cold, Metal+Lightning, Fire+Cold, and Fire+Lightning. But we also know that we can get Metal+Fire (Brass) and Cold+Lightning (Storm). The chances of getting a Brass or Storm are pretty close to each other. That makes it seem like the odds are predeterinedly set to favor the offspring being one of the parents. The mixes (Mine, Firefly, Scorch, and Magnetic) all have about 10% chances. Steel is way up there, closer to 25%, and Sun is down at 7.5%. Rainbow is abysmally low at 1%. This indicates that the probabilities are probably set with some sort of special scheme.