The stat is multiplicative, but i dont think you technically benefits less from it. The number just seems smaller but it doesnt lie. Lets say you have a 120 sec cooldown, 20% CDR knocks that down to 96 second, (24 second reduction), another 20% knocks that down farther to 76.8 (19.2 reduction). So sure its 19 instead of 24 but it's STILL A 20% REDUCTION.Quote from Isildien1109You see, there's this thing called diminishing returns. The more of a stat you have, like cdr. the less you actually benefit from it. That's how scaling works.
Just posting this because lots of people seems to equal "Diminishing Returns" with "Diminishing Value", which is just flat out innacurate.
Example of Diminishing Value: Dexterity, cant find current RoS values, but in vanilla, 1 Dexterity gave .1% dodge but suddenly at 101 dexterity, each point gave .025%. That's the literal definition of "Having less value because you have more of it"