How to increase your chances of getting foundables from challenges
There are charts out there that claim to have the probabilities of getting challenge and family foundables listed. After thousands of challenges, I have found these charts to be highly inaccurate. If you look at some parts of the charts, you will notice that not enough entries have been entered to obtain even remotely accurate results. It takes hundreds of instances of a challenge to start to get accurate predictions.
I have found better methods for obtaining fragments.
To improve your likeliness of obtaining certain challenge foundables, open up the Chamber Rewards page. Foundables to the left have a higher % chance to appear.
If you want to increase the chance of obtaining a family foundable, pay close attention to the possible rewards. If the fragment that you want appears, there will be a higher probability of it being the reward.
You can update your possible rewards by backing exiting the chamber, then selecting a new runestone; or by clicking the runestone, then changing it to a different runestone.
NOTE: You still have a chance to receive no reward and it does not guarantee that the fragment will be the reward, even in Dark V. It just increases the % of that fragment as the reward.


Comments
I feel I have had the opposite happen - if the family foundable is the first on my list (your second screenshot), it’s almost always not the one I get 🤷🏻♀️
Looking at the numbers in the charts, I honestly wouldn’t be surprised if family foundables are all a relatively equal balance (except likelihood of getting any foundable, which we know increases with difficulty) and the difference in numbers is just RNG.
Yes @BenTiger, it does seem that things are in order of probability. The charts and data were collected before the rewards screen was active.
For family fragments, the data was also before new fortress fragments were introduced for many families.
Having said all that, I am very grateful for all the research done by those players. I have benefited greatly as a result.