How to interpret challenges in the CK guide to HH?

[subbuglio]

Hi,
I'm running through the db1 part of the CK guide, and the attribute checks have always a fixed target.
For example, page 65, in TRAVEL: "they must make a dexterity check of 12 or better"
What's the suggested number to subtract to that to get the challenge level?

[Treebore]

I treat that as errata. They should have it phrased as making a CL 0 DEX check. The way they phrased it infers its always a Prime check. It badly infers it, at that. So I just treat it as a CL 0 DEX check. IE Prime beats a 12, non Prime has to beat an 18.

[subbuglio]

Yep I thought that was the right interpretation, but I wasn't sure the author used 12 as base for that.
Thank you!