MArcomage

A lot of discarding cards and keywords have this in their description, but I observe that when there's an option between discarding two uncommons, the choice is made randomly.

I'd suggest the system rate cards in highest rarity as follows:
1) Card rarity
2) Card overall cost
3) Card keyword

I usually perceive highest rarity meaning that the highest-costing or more-keyword-filled card is considered of highest rarity among other cards with the same rarity. What do you guys think?

I think that the way it behaves now is the way the description implies. No confusion here.

If this behavior were to be reworked such that you can be certain which card will be targeted, each individual card and effect to which this applies would have to have its balance reconsidered. I wouldn't want to have that task.