Uncanny luck:

5% resistance, 5% of Hits converted to Crits

 

What does "resistance" mean?

I checked the character sheet and it does not affect Deflection and other resistances.

Its ability description says "gain a small chance to completely avoid any attack [...]". So I assume it is an extra roll check in the attack resolution. What I don't know is if it checks before or after accuracy, which would affect the value of this passive, though 5% chance is rather negligible if not stacking with other similar effect.