Luck

Luck gives small bonuses to many combat attributes.

Gains per point:

Accuracy:             .40
Defense:              .40
Critical hit chance:  .30
Physical save:        .175
Mental save:          .175
Spell save:           .175

In addition, each point gives 0.2% chance to not break stealth (same as Unseen Actions), and 0.2% chance to avoid your own AoE effects (similar to Spellcraft).