partial cooldowns?

Here's a stupid thought to start the day - what if the cool-downs of various abilities were replaced with a chance of success mechanic. Thus, Bestial Wrath would be available with a 100% chance after 2 minutes, and a degraded chance before that time - it would have a 50% chance of working after 1 minute, and a 75% chance after 1:30. Failure would result in the cool down timer restarting, as well as the full resource cost.

How might this affect your game play?

I know I'd stop spamming my Feign Death button while stun locked, and weaving Arcane Shot into my shot rotation would be trickier. The lazy macro I use that attempts to cast Kill Command after every Steady Shot would need to be tossed out. That said, I'd definitely know there will be a few hail Mary moments where a partial chance of success is better than getting wiped - how cool would it be to get the kill shot on a boss as he's heading towards me, knowing I've only got a 10% chance of the shot even working?