Accessing the tooltip of a skill in combat should show the total percent chance of any effects, including the skill shard bonus as well as any talisman percent chance.

Ex: a character has a 25% crit chance with a basic attack. What is the chance while wearing chance talisman?

Another character has a “chance” passive, and they are also wearing a chance talisman. Does it make a difference, or is it the same percentage?

When you double up passive/skill/talisman effects, does it roll separately for each or does it add them together for one roll?

It would be a lot easier to understand what is happening if the tooltips themselves displayed the actual chance of effects occurring vs the default skill text