During my gameplay today, I noticed the following: Sometime 
skills do no (I mean literally no damage) despite 
animation and sounds effects taking place and 
magicka being subtracted from my pool. In short, it feeling like you shoot blanks.
Some additional info a gathered:
I wholeheartedly hope this is a 
bug not a feature as it (at least in my case) makes the 
game significantly less enjoyable or even 
near implayable. I would dare to say this is even more gamebreaking than the memory leak and/or the unintended buff of veteran mobs.
Please share you experience / comments and theories. The 
more activity this thread sees, the sooner the 
issue get noticed (and ultimately fixed) by the developers (assuming this is a bug in the first place).