Halves casting weapons

when you have a wand with Halves casting time of <attribute> spells (Chance: 20%) and a off hand with Halves casting time of <attribute> spells (Chance: 20%) does it stack to a 40% chance or is it still a 20% chance?

One of the many times this has been tested was reported here.

The check for each mod is an independent event. If the math doesn't make sense to you, maybe this explanation will help.

If not, try the examples here.

Alright, cleaning up this thread: the probability is not 36/4. Anyone who says 36/4 is screwing up their math and I'm tired of it. It is 32/4. Here's a graphical presentation I put together a while back:



(You could have also computed the half recharge by subtracting the quarter and normal percentages from 1.)

Just to note though, for halved skill recharge you cannot get quarter recharge since the July 17 update. But we're talking about casting time here which still can achieve quarter cast.