Does improves (something) things stack?

Dzarg

Pre-Searing Cadet

Join Date: May 2005

23 May 2005 at 21:39 - 1

I was wondering if I have for example wand with "improves Casting speed using Divine Favor skills (Chance: 20%)", and a focus item with the same, do they stack in any way? Do I get 40% chance? Do I get 20% chance first and if that fails I get another 20% chance? Or simply just 20% chance? Or something else?