Do the "narrow surfaces" need to be made of stone or earth to use the Rock Runner feat in Pathfinder 2e?

Question

I have a doubt about the Rock Runner feat in PF2e.

Your innate connection to stone makes you adept at moving across uneven surfaces. You can ignore difficult terrain caused by rubble and uneven ground made of stone and earth. In addition, when you use the Acrobatics skill to Balance on narrow surfaces or uneven ground made of stone or earth, you aren't flat-footed, and when you roll a success at one of these Acrobatics checks, you get a critical success instead.

The highlighted part is not clear about allowing to balance on narrow surfaces also if they are not made of rock, stone, earth. Is my interpretation correct?

Answer 1

Rock Runner only works on earth or stone

The Balance action is used for both Narrow Surfaces and Uneven Ground. The Rock Runner feat specifically gives a bonus on Balance checks involving stone or earth.

While your reading of the text could be considered syntactically correct, it ignores context clues from the rest of the passage.

Ambiguous Rules Sometimes a rule could be interpreted multiple ways. If one version is too good to be true, it probably is. If a rule seems to have wording with problematic repercussions or doesn’t work as intended, work with your group to find a good solution, rather than just playing with the rule as printed.

While your interpretation isn't necessarily too good to be true, it's pretty clearly not the intended reading either.

Answer 2

If you're asking whether "made of stone or earth" applies to the narrow surface as well as the uneven terrain, the answer is yes. This is clear from the context of the rule block.

Even without the contextual clues, I would still default to that interpretation. Not everyone writes clearly enough, but if the intent were to separate out the narrow-surface from the earth-and-stone, the sentence would probably be written a little differently.