Originally Posted by moebius92
For example, take Shield-taunt which is the only guardian skill I can think of that is purely threat (Fray the Edge and Litany of Defiance both have debuffs). In my combat, I get messages like "<name> scored a hit with Shield-taunt on the Foraging Brown-bear." Which makes sense, since there's also miss and resist messages - so you can use it to track frequency of outcomes on your skills. Heck, you can track it against specific target types.
In fact, I think the only way to use a skill and not have to generate some sort of foot print in the combat log is to use a AoE skill with no targets in range. And in that case, you can track the power drop or the morale drop. So... if you've got a skill that has no power cost or morale cost, and it's AoE, and you use it with no targets in range, then yes. There will be absolutely no sign that it was ever used. Of course, it probably has no effect, and I'm not sure there actually are any skills that meet that criteria, but other than that, those skills can be missed.
Ok then, I wasn't aware that skills that didn't do damage showed up in the log. I guess the only thing in the way is figuring out a value for each skill that would affect threat, so a threat list could be created. But that's a whole lot of trial and error involved.