Ty very much for the quick reply, makes complete sense that way. Just not what I'm used to "traditional" CDR being in games.Quote from Volpethrope
Take the base cooldown and write is as "number of cooldowns per minute." (or hour or day or whatever, the specific unit doesn't matter, as long as it's consistent) Multiply it by your CDR percent as a decimal added to 1.
Example: Explosive Blast has a 6 second cooldown, which would be ten cooldowns per minute. You have 100% CDR, which we'll express as 1, and add it to 1, giving us 2. Multiply the number of cooldowns per minute by this number, to get 20. Now we can divide 60 seconds by 20 to get 3 seconds, the new cooldown.
If you had, say, 35% CDR, Explosive Blast's cooldown would be reduced to about 4.4 seconds. 1000% CDR would reduce it to about half a second.
TL;DR: Don't think of it as a percent decrease to your cooldowns, because that would allow you to remove your cooldowns entirely. Think of it as a percentage increase to how many times you can use an ability in a given timeframe. 50% CDR means you can use Explosive Blast (or whatever) 50% more times in the same timeframe than if you had 0% CDR.
Would still love to know why we don't see CDR and resource reduction on our tooltips.