>>5768737> Wouldn't that ruin the tension and excitement.Well...
You could give a vague challenge rating for each option, then have players roll [1d100, avg of 3] or [1d100, rand of 3].
This would preserve player anticipation and give you leeway to fudge things a little if the need arises.
At the end of the day, you're providing an interesting adventure with some pretty good accompanying art.
Only the most pedantic of powergamers would complain about the lack of absolute mechanical transparency.