Originally posted by Sunder the Gold
So the Clash keyword would probably be used to denote the exceptions.
In which case, it needs errata, since at the moment it only restricts use by forbidding use against Charms with the Counterattack keyword.
Thunderclap Rush Attack acts like the Clash keyword actually enables rather than restricts, too.
Or it's just a case of "things only let you force a clash if they say they let you force a clash
," which I'm fine with.